Chemoenzymatic synthesis of both enantiomers of α-tocotrienol

The stereoselective acylation of the achiral chromanedimethanol derivative 1 by vinyl acetate in the presence of Candida antarctica lipase B gave the (S)-monoester 2 in high enantiomeric purity (ee⩾98%). Enzymatic hydrolysis of diesters of compound 1 failed to give (R)-monoester 2 in good yield and high ee. Thus, both enantiomers of α-tocotrienol were synthesized from the (S)-monoester 2.