Optical Resolution for Alcohols and Thiols

Compound 1, developed by Nemoto et al., is an optical resolving agent for alcohols and thiols. Using this reagent under a simple protocol, chiral alcohols and thiols can be easily obtained with high optical purity. For example, 1 reacts with racemic alcohols in benzene or dichloromethane in the presence of an acid catalyst to form a mixture of diastereomers 2. These diastereomers can then be separated on the thin layer chromatography (TLC), and easily isolated by silica gel column chromatography. Methanolysis of the isolated compounds 2 in the presence of an acid catalyst affords the chiral alcohols. Moreover, it is possible to recover 3 and reuse 1 derived from 3. Since this process proceeded under a mild condition, it has been expected to be a useful method to obtain chiral alcohols and thiols.