JPS5912097B2 - Method for producing cyclic compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pharmaceutically useful general formula [where n is an integer of 1 or 2, and A has a carboxyl group, a lower alkoxycarbonyl group, or a lower alkyl or halogen atom as a substituent] Indicates an optional benzoyl group.

] This invention relates to a method for producing a novel cyclic compound represented by: More specifically, the present invention has the following features: (1) General formula [wherein n and A have the same meanings as above.

Method for producing a compound represented by the general formula [1] (2), which comprises solvolyzing the compound represented by the general formula [1] in the presence of water or a lower aliphatic alcohol. Same meaning as above.

] A compound represented by the general formula [where n and A have the same meanings as above] is produced by reacting a compound represented by the following with 1,3-dithiane in the presence of a base.

] The compound represented by the above general formula [
This is a method for producing a compound represented by the general formula [1], which comprises solvolyzing the compound represented by the formula [1] in the presence of water or a lower aliphatic alcohol. In the general formula [1], [], [], [], the benzoyl group represented by A is a linear or branched lower alkyl group having about 1 to 4 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, Sec-butyl, t-butyl group), halogen atom (e.g., fluorine, chlorine, bromine, iodine atom) as a substituent, and these substituents have 1 or 2 The benzoyl group may be substituted at any position of the benzoyl group, individually, the same or different.

Furthermore, in the general formula [1], [], [], [], R
Examples of the lower alkoxycarbonyl group represented by include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, Sec-butoxycarbonyl, t-ptoxycarbonyl, and the like.

In addition, examples of the alkyl group represented by R in the general formula [1] include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, Sec-butyl, t
-butyl esters, etc. The compound represented by the above general formula [] can have two types of structures, [a] and [b] below, and either of them can be subjected to the solvolysis of the present invention, but especially [a] ] is conveniently used.

[In the formula, n and A have the same meanings as above.

] In the present invention, the compound of the general formula [ ] is subjected to solvolysis (
SolvOlysis) to obtain a compound of general formula [1].

Solvolysis includes hydrolysis using water as a molten catalyst,
Alcoholycolysis using lower aliphatic alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, Sec-butanol, t-butanol, etc.) as a solvent is common. Solvolysis is generally carried out in the presence of a catalyst,
Examples of catalysts include hydrogen halides (e.g., hydrogen chloride,
(hydrogen bromide, hydrogen iodide, etc.), mineral acids such as sulfuric acid, phosphoric acid, polyphosphoric acid; formic acid, acetic acid, para-toluenesulfonic acid,
Organic acids such as β-naphthalene sulfonic acid, heavy metal salts (
For example, mercury chloride, mercury bromide, mercury fluoride, mercury sulfate, copper chloride, copper bromide, etc.) are used. These catalysts may be used alone or in combination of two or more. The reaction temperature varies depending on the reaction conditions such as the solvent and catalyst used, but generally it may be under cooling, at room temperature, or under heating. There is no particular limitation on the reaction time. B in product [1]
varies somewhat depending on the solvolysis conditions, and the target compound having the intended B can be obtained by selecting the reaction conditions. For example, when a compound [ ] is hydrolyzed, a compound in which R is a hydrogen atom is obtained as a product [ ]. Furthermore, when the compound [] is subjected to alcoholysis, a compound in which B is a lower alkyl group corresponding to the lower aliphatic alcohol used is obtained as the product [1]. Furthermore, by selecting the reaction conditions of the above-mentioned solvolysis step, it is also possible to obtain the target compound [1] in which the group represented by A of the compound [] is esterified or de-esterified. The above-mentioned compound [] is, for example, the above-mentioned general formula []
is advantageously prepared from a compound of

That is, the present invention provides a method for converting a compound [] to a target compound [1]
It also provides an industrially advantageous method for manufacturing. In this method, first, the compound [] and 1,3-dithiane are reacted in the presence of a base. Examples of bases include alkali metal hydroxides (e.g., sodium hydroxide, potassium hydroxide, etc.), alkali metal hydrides (e.g., sodium hydride, lithium hydride, etc.), alkali metal alcoholades (e.g., sodium methylate,
sodium ethylate, sodium t-butyrate, potassium t-butyrate, sodium t-amylate, etc.), amides of alkali metals (e.g., sodium amide, potassium amide, lithium amide, sodium piperidide, potassium piperidide, lithium piperidide) n-butyllithium, triton-B, and the like. This reaction is generally carried out in the presence of a solvent, and the solvent is not particularly limited as long as it is inert to the reaction, such as ethers (
For example, diethyl ether, tetrahydrofuran, dioxa'/, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethylene glycol dimethyl ether, etc.) Benzene, toluene, xylene, water, etc. are advantageously used. The amounts of 1,3-dithiane and base used in the reaction are not particularly limited, but are preferably about 1 to 2.0 mol each per 1 mol of compound []. Further, the reaction temperature is preferably about -30°C to the boiling point of the solvent, and the reaction time is preferably about 5 to 25 hours. By dehydrating the thus produced compound of general formula [], the compound of general formula [] can be obtained. I can do it.

The compound [] used in this reaction can be isolated and purified by a conventional method, but it can also be used in this reaction without being isolated and purified from the reaction solution of the previous step. Examples of dehydrating agents used in this reaction include mineral acids (e.g., sulfuric acid, phosphoric acid, phosphorous acid, hydrochloric acid, etc.), phosphorous oxychloride, thionyl chloride, arylsulfonic acids (e.g., benzenesulfonic acid, p-toluenesulfonic acid, β- naphthalene sulfonic acid, etc.)
, acetic acid and its derivatives (eg, trifluoroacetic acid, trichloroacetic acid, etc.), lower alkylsulfonic acids (eg, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, etc.), and the like are advantageously used. Further, the liquid medium used at this time is not particularly limited as long as it does not interfere with the reaction. The reaction temperature is about 150° C. under cooling, and there are no limitations on the reaction time and the like. The target compound [] is obtained by subjecting the thus produced compound [] to the above-described solvolysis reaction.

In the case of this reaction as well, the compound [] can be isolated by a conventional method, but it can also be used in this reaction without being isolated and purified from the previous reaction solution. In addition, in the step of reacting the compound [] with 1,3-dithiane to obtain the compound [], the compound [] may be dehydrated to obtain the compound [] all at once, or the compound [] may be dehydrated. In the step of obtaining the compound [], the generated compound [] may be solvolyzed to obtain the target compound [1] all at once.

When the compound of general formula [1] produced by hiding is obtained as a free carboxylic acid, if necessary, it may be treated by a known treatment method (e.g., formation of a salt by neutralization, etc., using alcohol in the presence of an acid). This may be converted into a derivative at the carboxyl group by esterification, amidation by reacting with an amine, amidation by converting it into an acid halide and then reacting with an amine, etc.), or conversely, the derivative at the carboxyl group can be converted into a derivative at the carboxyl group by a process known per se. Methods (eg hydrolysis in the presence of alkalis or acids) can also lead to the free carboxylic acids.

Further, the derivative at the carboxyl group can be led to other derivatives by means known per se (for example, amidation in which an ester is reacted with an amine). Examples of derivatives of these carboxyl groups include, in addition to the above-mentioned esters, unsubstituted amides, substituted amides, salts, and the like. Substituted amides include hydroxamic acid (-CONH
OH), hydrazide (-CONIINH2), or a carbon number 1 in which the alkyl moiety may be substituted with a hydroxyl group
~3 mono- or di-lower alkylamines (e.g., ethanolamine, diethanolamine, methylamine, dimethylamine, ethylamine, diethylamine, propylamine, etc.), arylamines (e.g., aniline, methylaniline, etc.), 1 to 2 5-6 with nitrogen atom
membered cyclic amines (e.g., morpholine, pyrrolidine, piperidine, piperazine, N-monosubstituted piperazine, etc.), N-
Aralkyl-substituted amines (e.g., benzylamine, α-methylbenzylamine, phenethylamine, etc.), alkyl- or aryl-substituted hydrazines (e.g., methylhydrazine, dimethylhydrazine, phenylhydrazine, etc.)
Examples include N-mono or substituted amides corresponding to organic amines such as.

Salts include, for example, alkali metals (e.g. sodium,
salts with metals such as alkaline earth metals (eg, calcium, magnesium, etc.), aluminum, ammonium salts, and salts with the above-mentioned organic amines. The target compound thus obtained can be separated and purified by methods known per se, such as distillation, recrystallization, column chromatography, etc. Since the compound of general formula [1] obtained by the method described above has an asymmetric carbon at the 1-position in the molecule, it can be divided into d- and l-optical optical isomers by a method known per se. can.

That is, the racemic free acid is dissolved in a suitable inert solvent such as chloro1form, acetone, benzene, hexane, ether, etc., and reacted with an optically active base.
The obtained salt or amide can be separated into diastereoisomers depending on their solubility, and then treated with an acid to isolate the optically active form of the free carboxylic acid derivative. Alternatively, an ester is prepared from a racemic free acid and a suitable optically active alcohol, and this ester is, for example, recrystallized.
Optically active free carboxylic acid derivatives can be isolated by separating diastereoisomers by methods known per se such as distillation or chromatography, and then hydrolyzing the ester in the presence of an acid or base. be able to. The optically active base used here includes, for example, quinine, brucine, cinchonidine, cinchonine, dehydroabititylamine,
Amines such as hydroxyhydrindamine, tantylamine, morpine, α-phenylethylamine, phenyloxynaphthylmethylamine, quinidene, stoikinine,
These include basic amino acids such as lysine and arginine, and amino acid esters. Examples of optically active alcohols include borneol, menthol, and 2-octanol. The compound of general formula [1] obtained by optical resolution as described above can be converted into an optically active derivative in its carboxyl group by a method known per se as described above. Compounds of the general formula [] and their carboxyl group derivatives produced by the method of the present invention, especially those in which A is a benzoyl group which may have a lower alkyl or halogen atom as a substituent, are It has remarkable anti-inflammatory, analgesic, and antipyretic effects, and is useful as a medicine such as an anti-inflammatory, analgesic, and antipyretic agent.

When A is a carboxyl group or a group derived therefrom, A can be converted into a benzoyl group which may have a lower alkyl or halogen atom as a substituent by subjecting it to a Friedel-Crafts reaction. When the target compound of the present invention is used as these medicines, the dosage is as follows:
It is selected as appropriate depending on the administration route, purpose of administration, etc.
For example, when administered for the purpose of treating rheumatoid arthritis, osteoarthritis, osteoarthritis, spondylosis, arthralgia, low back pain, etc., the usual dose is approximately 10 to 100,019 ml per day for adults.
is administered orally in the appropriate dosage form of tablets, capsules, or powders, or in a single adult dosage of about 5 to 500! ! It is preferable to administer No. 19 parenterally as an injection, suppository, or the like.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but it goes without saying that the present invention is not limited to these Examples.

Example 1 (a) 3.67 ml of 1,3-dithiane was dissolved in 100 ml of anhydrous tetrahydrofuran, cooled to 30°C in a nitrogen gas stream, and 10 ml of a 20% hexane solution of n-butyllithium was added dropwise over about 15 minutes while stirring. do.

After the addition was completed, the mixture was stirred at the same temperature for 2 hours and then at -5°C for 30 minutes. This solution was cooled again to -20°C, and while stirring, a solution of 7.17 4-benzoylindan-1-one dissolved in 75 ml of anhydrous tetrahydrofuran was added dropwise. After dropping, stir at the same temperature for 1 hour, then add O
Leave overnight at °C. Next, the solvent is distilled off under reduced pressure. Add 15 ml of dilute hydrochloric acid to the residue and extract with ether. The extracted layer is washed with water and saline and dried. The residue obtained by distilling off the solvent under reduced pressure was subjected to silica gel column chromatography (silica gel 5007, benzene monoethyl acetate 20:1).
(elution with a mixed solvent). As an oil, 2-(4
-benzoyl-1-hydroxy-1-indanyl)-1
- 3-dithiane is obtained. The infrared absorption spectrum (neat) of this product is 1660c! The absorption by ketone is shown at n-1, and the absorption by hydroxyl group is shown at 3450CTrL-1, which agrees well with the structure. (b) 2-(4-benzoyl-1
-hydroxy-1-indanyl)-1,3-dithiane1.
Dissolve 47 in 300 ml of benzene and add 600 η of para-toluenesulfonic acid.

Reflux for 3 hours while dehydrating using a dehydrating reflux device. After cooling, wash with water, sodium bicarbonate aqueous solution, and water, and dry. When the solvent was distilled off under reduced pressure, 2-
(4-benzoyl-1-indanilidene)-1,3-dithiane is obtained. This product is used in the next reaction without purification. (c) 150m to 0.8f of 2-(4-benzoyl-1-indanilidene)-1,3-dithiane
Add 1 t of glacial acetic acid and 5011 t of concentrated hydrochloric acid, and reflux for 3 hours.

The solvent was distilled off under reduced pressure, and the residue was extracted with ether. After washing the ether layer with water, it is extracted with a 5% aqueous sodium carbonate solution. The extracted layer is washed with ether and then acidified with hydrochloric acid. The precipitated oil is extracted with ether. The extracted layer is washed with water and saline, and then dried. The residue obtained by distilling off the solvent under reduced pressure was diluted with benzene-cyclohexane (7
:20). 4-benzoylindane-1-carboxylic acid is obtained as crystals with a melting point of 100-102°C. Elemental analysis value (Cl7Hl4O8) Calculated value C76.67; H5.3O Experimental value C76.37; H5.2l 3.2t of 4-benzoylindane-1-carboxylic acid obtained above and 1.70r of cinchonidine were mixed in 60% acetone.
Add to m1 and shake to dissolve.

After standing at room temperature overnight, the precipitated crystals were collected and recrystallized twice from acetone to obtain (1) cinchonidine salt of -4-benzoylindane-1-carboxylic acid with a melting point of 189-19.
Obtained as colorless crystals of [α]-132.28 (C=1, CHCl3) at 2°C.

Elemental analysis value C36H36O4N2 Calculated value C77. l2;H6.47:N5. OO experimental value C77. 18: H6.28; N4.9l Dissolve this product in chloroform and shake twice with dilute hydrochloric acid to remove cinchonidine.

The chloroform layer is washed with water and then dried with magnesium sulfate.
When the solvent was distilled off under reduced pressure, (1)-4-benzoylindane-1-carboxylic acid was converted to [α]2-66.4-(C=1
, MeOH) as a colorless oil. Elemental analysis value C,7Hl4O3 Calculated value C76.67; H5.3O Experimental value C76.25; H5.37 The mother liquor from which the first crystals were collected was concentrated under reduced pressure, and 1.7 t of cinchonidine and 120 ml of acetonitrile were added to the residue. Add to the mixture, shake while heating, and leave at room temperature overnight.

The precipitated crystals were collected and recrystallized three times from acetonitrile to give (d) cinchonidine salt of -4-benzoylindane-1-carboxylic acid with a melting point of 180-183°C, [α]2d1
1.2 (C=1CHC13) as colorless crystals. Elemental analysis value C36C36O4N2 Calculated value C77. l2; H6.47; N5. OO experimental value C77. 15; H6.42; N4.72 Dissolve this product in chloroform and shake twice with dilute hydrochloric acid to remove cinchonidine.

The chloroform layer is washed with water and then dried with magnesium sulfate.
When the solvent was distilled off under reduced pressure, (d)-4-benzoylindane-1-carboxylic acid was obtained as [α]2d66.4l (C=1,
MeOH) as a colorless oil. Elemental analysis value
Cl7Hl4O3 Calculated value C76.67; H5.3O Experimental value C76.53; H5.3O (d) 25ml of thionyl chloride was added to 6.6y of 4-benzoylindane-1-carboxylic acid, and after standing overnight, the excess amount was determined under reduced pressure. thionyl chloride is distilled off.

Ether is added to the residue and ammonia gas is introduced. Collect a lot of the precipitated crystals, wash with water, dry, and then recrystallize from benzene. 4-benzoylindane-1-carboxylic acid amide is obtained as crystals with a melting point of 164-166°C.

Elemental analysis value Cl7Hl5O2N Calculated value C76.96; H5.7O; N5.28 Experimental value C76.78; H5.6l; N5.4l Example 2 2-(4- benzoyl
Dissolve 2.0 liters of 1-indanilidene)-1,3-dithiane in 200 ml of ethanol and cool on ice.

Hydrogen chloride gas was passed through the solution for 15 minutes, followed by ice cooling for 2 hours, and then left overnight at room temperature. After distilling off excess hydrogen chloride and the solvent under reduced pressure, water was added and the mixture was extracted with ether. The extracted layer is washed with water and then dried. The residue obtained by distilling off the solvent under reduced pressure was subjected to silica gel column chromatography (
Silica gel 200P1 elution solvent is purified using a benzene solution containing 2.5% ethyl acetate. 4-benzoylindane-1-carboxylic acid ethyl ester is obtained as an oil.

Elemental analysis value ClOHl8O3 Calculated value C77.53:H6. l6 Experimental value C77.4l; H5.97 Infrared absorption spectrum (neat) 1720CTrL-1 (carbonyl of ester) 16
50CfL-1 (carbonyl of ketone) Example 31
・3-dithiane 3,67 in anhydrous tetrahydrofuran 10
The mixture was cooled to -30°C in a nitrogen gas stream, and 10 ml of a 20% hexane solution of n-butyllithium was added dropwise over about 20 minutes while stirring.

After the addition was completed, the mixture was stirred at the same temperature for 2 hours and then at -5°C for 30 minutes. This solution is cooled again to -20 DEG C., and while stirring, a solution of 8.17 4-(p-chlorobenzoyl)indan-1-one dissolved in 75 ml of anhydrous tetrahydrofuran is added dropwise. After the addition was completed, the mixture was stirred at the same temperature for 1 hour, and then left at 0°C overnight. Next, the solvent is distilled off under reduced pressure. Dilute hydrochloric acid is added to the residue and extracted with ether. The extracted layer is washed with water and saline, and then dried. The residue obtained by distilling off the solvent under reduced pressure is subjected to a dehydration reaction without being purified. That is, the residue is dissolved in 350 ml of benzene and 600 η of para-toluenesulfonic acid are added. Using a dehydrating reflux device, reflux for 3 hours while dehydrating. After cooling, wash with water, aqueous sodium bicarbonate solution, and water. The residue obtained by distilling off the solvent under reduced pressure is hydrolyzed without purification. Add 150 ml of glacial acetic acid and 50 ml of concentrated hydrochloric acid to the residue, and reflux for 3 hours. The solvent was distilled off under reduced pressure, water was added to the residue, and the mixture was extracted with ether. After washing the ether layer with water, it is extracted with \% aqueous sodium carbonate solution. The extracted layer is washed with ether and then acidified with hydrochloric acid. The precipitate is extracted with chloroform, and the extracted layer is washed with water and then dried. The residue obtained by distilling off the solvent under reduced pressure was diluted with benzene.
When crystallized from cyclohexane (3:10), melting point 1
4-(p-chlorobenzoyl)indan-1-carboxylic acid is obtained as crystals at 37-139°C. Elemental analysis value Cl7Hl3O3Cl calculated value C67.89; H4
．． 36;Cll. 79 Experimental value C67.6l; H4.
2l; Clll. 9 liters of 4-(p-chlorobenzoino(he)indan-1-carboxylic acid obtained above) 3.1 t
and cinchonine 1.57 to 100 ml of acetone,
After heating and melting, add a small amount of activated charcoal and filter thoroughly.

▲ Let the liquid cool overnight, and then leave it at 0-5°C overnight. When a lot of precipitated crystals are collected and recrystallized from acetonitrile, (1)
The siliconine salt of -4-(p-chlorobenzoyl)indan-1-carboxylic acid is obtained as colorless crystals with a melting point of 193-196°C and [α] of 33.6 (C=1, CHCl3). Elemental analysis value C36H34O4N2Cl Calculated value C72.78; H5.77; N4.72 Experimental value C72.5l; H5.92; N4.72 Dissolve this product in chloroform and shake twice with dilute hydrochloric acid to remove cinchonine.

The chloroform layer is washed with water and then dried with magnesium sulfate.
The solvent was distilled off under reduced pressure, cyclohexane was added to the residue, and the resulting crystals were collected. When recrystallized from a mixture of benzene and cyclohexane (1:4), (1)-4-(p-chlorobenzoyl)indan-1-carboxylic acid has a melting point of 121
-122℃, [α]M-66.9 acid (C=1, MeOH
) is obtained as colorless crystals. Elemental analysis value Cl7Hl
8O3Cl calculated value C67,89; H4.36 Experimental value C67.72; H4.33 Example 4 By the same operation as in Example 3, 20% of 3.61 1,3-dithiane, 10m1f) n-butyllithium 4-(p-Methylbenzoyl)indan-1-carboxylic acid is obtained from 7.57 4-(p-methylbenzoyl)indan-1-one in hexane solution.

Melting point 129.5-131.0°C (Recrystallization solvent: benzene-cyclohexane 8:25) Elemental analysis value C,8Cl6
O3 calculated value C77. 12; H5.75 Experimental value C76.94; H5.6l Example 5 By the same operation as in Example 3, 3.6 V of 1.3 dithiane, 10 ml of a 20% hexane solution of n-butyryllithium, 8. 57 4-(p-chloro-m-methylbenzoyl)indan-1-one, 4-(p-chloro-m-
Methylbenzoyl)indan-1-carboxylic acid is obtained.

Melting point 115.0-116.5°C (Recrystallization solvent: benzene-cyclohexane 3:20) Elemental analysis value Cl8Cl5
O3Cl calculated value C68.68; H4.8O; Clll. 27 Experimental value C68.5l; H4.59; Clll. 54 Example 6 By the same operation as in Example 3, 5- Benzoyl-1,2,3,4-tetrahydro-1-naphthoic acid is obtained.

Melting point: 164-165°C (recrystallization solvent: benzene) Elemental analysis value: Cl8Hl6O3 Calculated value: C77. l3; H5.75 Experimental value C77. 15; H5.7O Example 7 By the same operation as in Example 3, 1,3-dithiane of 3,6f7, 20% hexane solution of n-butyllithium (10ml1f), 5-(p-methylbenzoyl of 7.91) )−
1-tetralone to 5-(p-methylbenzoyl)-
1,2,3,4-tetrahydro-1-naphthoic acid is obtained.

Melting point 102-103℃ (recrystallization solvent: cyclohexane)
Elemental analysis value Cl9Hl8O3 Calculated value C77.53; H6. l6 Experimental value C77.4l; H5.97 Example 8 By the same operation as in Example 3, a 20% hexane solution of 3.6V 1.31 dithiane, 10me(l) n-butyllithium, and 8.5f7 5-(p-chlorobenzoyl)
-1-tetralone to 5-(p-chlorobenzoyl)
-1,2,3,4-tetrahydro-1-naphthoic acid is obtained.

Melting point 152.5-153.5°C (recrystallization solvent: benzene-hexane) Elemental analysis value Cl8Hl5O3Cl Calculated value C68.68; H4.8O: Clll. 27 Experimental value C68.75; H4.83; Cllll.

25 Example 9 By the same operation as in Example 3, from 3.6y of 1,3-dithiane, 10ml of a 20% hexane solution of n-butyllithium, and 5.3V of 1-oxoindan-4-carboxylic acid methyl ester , indane-1,4-dicarboxylic acid is obtained.

Melting point 245.5-248°C (recrystallization solvent: acetone) Elemental analysis value CllHlOO4 Calculated value C64. O7; H4.89 Experimental value C64,05; H4.73

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, n is an integer of 1 or 2, and A is a carboxyl group, a lower alkoxycarbonyl group, or a lower alkyl or halogen atom as a substituent. Indicates a benzoyl group which may have. ] A general formula characterized by solvolyzing a compound represented by the following in the presence of water or a lower aliphatic alcohol ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, n and A have the same meanings as above. , and R represents a hydrogen atom or a lower alkyl group. ] A method for producing a compound represented by 2 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. Shows good benzoyl group. ] The general formula produced by reacting the compound represented by 1,3-dithiane with 1,3-dithiane in the presence of a base ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, n and A have the same meanings as above. ] The general formula produced by dehydrating the compound represented by ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, n and A have the same meanings as above. ] A general formula characterized by solvolyzing a compound represented by the following in the presence of water or a lower aliphatic alcohol ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, n and A have the same meanings as above. , and R represents a hydrogen atom or a lower alkyl group. ] A method for producing a compound represented by