SYNTHESIS OF HOMOCHIRAL 4-METHYLCARBOMETHOXY-γ- AND 5-METHYLCARBOMETHOXY- δ-LACTONES VIA ENANTIOSELECTIVE CATALYTIC HYDROGENATION OF 3-OXOALKANEDIOATES
ABSTRACT Asymmetric hydrogenation of dimethyl 3-oxohexanedioate (1) and 3-oxoheptanedioate (5), catalyzed by cationic BINAP-Ru(II) complex (R)-2, afforded corresponding secondary alcohols 3 and 7 with very high enantiomeric purity (>98% ee). These alcohols 3 and 7 were then transformed into enantiomerically pure title γ- and δ-lactones 4 and 9, respectively.