1,3-Dioxolanone alcohols, prepared via the addition of chiral lithiumenolates of 1,3-dioxolan-4-ones to aldehydes, are suitable intermediates for the synthesis of chiral trisubstituted isoserines or trisubstituted 3-hydroxy-β-lactams. In particular, the methyl ester of 2-methyl-3-(2-furyl)isoserinic acid and two 3-methyl-3-hydroxy-β-lactams bearing either a 2-furyl or a phenyl substituent at C-(4)