PURPOSE: To industrially obtain the titled compound which is d-α-tocopherol intermediate, by using (S)-citramalic acid as a raw material, reductively subjecting a novel rearrangement product obtained from an optically active sulfide and substituted phenol to desulfur and deprotecting and cyclizing the treated rearrangement product.
CONSTITUTION: A novel compound expressed by formula I (X is protecting group of OH) is reductively subjected to desulfur and deprotecting and then cyclized to provide the chroman derivative expressed by formula II [e.g. (S)-6- hydroxy-2,5,7,8-tetramethylchroman-2-methanol, etc.]. The compound expressed by formula I is obtained by subjecting an optically active sulfide obtained from (S)-citramalic acid to 2,3-sigmatropy rearrangement reaction with trimethylhydroquinone derivative expressed by formula IV. According to the above-mentioned method, optically active α-tocopherol is advantageously produced without requiring dl resolution in high yield on a large scale.
MIYAMOTO OSAMU
INOUE SEIICHI
SEHATA KATSUFUMI
