Takeda Chemical Industries, Inc.

Takeda Pharmaceutical Company Limited

Toru Yamano

Naohiro Taya

Kunio Takanohashi

Akio Ojida

Mitsutaka Tanaka

Isao Aoki

Mitsuru Kawada

Kazuo Nakahama

Mari Adachi

Masayuki Yamashita

Haruomi Honda

The present invention provides a method for producing an optically active &#x3b2;-hydroxy ester compound represented by the general formula: wherein wherein the ring may be substituted and the like, wherein Rand Rare as defined above with a compound represented by the general formula: wherein R, Rand Rare as defined above, and X is a halogen atom.

Method for producing optically active compound

The present invention provides a method for producing an optically active &#x3b2;-hydroxy ester compound represented by the general formula: wherein Rrepresents an optionally substituted hydrocarbon group and the like, Rrepresents a nitrogen-containing heterocyclic group different from R, which is represented by the general formula: wherein the ring may be substituted and the like, Rrepresents an optionally substituted hydrocarbon group and the like, Rand Rrepresent, the same or different, a hydrogen atom, a halogen atom and the like, the symbol '*' represents an optically active center, which comprises reacting in the presence of a cinchona alkaloid and the like a compound represented by the general formula: wherein Rand Rare as defined above with a compound represented by the general formula: wherein R, Rand Rare as defined above, and X is a halogen atom.

Process for production of optically active compounds

Process for producing optically active naphthalene derivative and optical resolver therefor

L-ascorbic acid is produced by allowing an acid to act on 2-keto-L-gulonic acid in a mixture solvent of an inert organic solvent and an aliphatic ketone in the presence of water and a surfactant. The method produces L-ascorbic acid in a high yield 90% or more and is an industrially advantageous method.

Production of L-ascorbic acid

A process for producing L-ascorbic acid, which comprises reacting 2-keto-L-gulonic acid with an acid in an ether or an inert organic solvent containing an ether in the presence of water and a surfactant.

Process for producing L-ascorbic acid

There are disclosed a compound of the general formula (I): ##STR1## wherein the group R--CO-- is an acyl group and its production. There is also disclosed a process for producing optically active (.+-.)-(3a.alpha., 4.alpha., 6a.alpha.)-tetrahydro-4-acetoxy-1,3-dibenzyl-1H-thieno[3,4-d]imidazol-2(3H )-one by using the compound (I). The compound (I) can be used as an intermediate for producing D-biotin which is useful as medicaments and feed additives for animals.

Intermediates for D-biotin synthesis and their production

6-O-(2-keto-L-gulonoyl)-L-ascorbate substantially free from 2-keto-L-gulonic acid is produced by allowing an acid to act on 2-keto-L-gulonic acid in an inert organic solvent and recovering 6-O-(2-keto-L-gulonoyl)-L-ascorbate from the reaction mixture. 6-O-(2-keto-L-gulonoyl)-L-ascorbate is more fat-soluble than L-ascorbic acid and is expected of the use as a prodrug for L-ascorbic acid that can be absorbed from the intestinal tract.

Ascorbic acid ester

A novel 2-lower alkyl-4-amino-5-substituted iminopyrimidine compound represented by the formula: ##STR1## wherein R is a lower alkyl, and Y is hydroxyl or amino which may be protected or a salt thereof is obtainable by allowing a formylpyrimidine compound represented by the formula: ##STR2## wherein R is a lower alkyl to react with a compound represented by the formula H.sub.2 N--Y, wherein Y is hydroxyl or amino which may be protected, or a salts thereof. The iminopyrimidine compound gives the known pyrimidine compound represented by the formula: ##STR3## wherein R is as defined above in high yield. Therefor, the process is very useful as an industrial production method.

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Itami, Japan

Toru Yamano