How is (3S)-1,3-Butanediol (CAS: 24621-61-2) typically synthesized?

(3S)-1,3-Butanediol is commonly synthesized via hydrogenation of 1,3-butenedione catalyzed by palladium-based catalysts. The process yields a mixture of (3S) and (3R) isomers, with the (3S) isomer being the more preferred. Other methods include enzymatic reduction of ketones or racemic 1,3-Butanediol, which can be resolved to obtain the (3S) isomer with high enantiomeric excess.