A convenient new synthetic approach has been established to prepare S-[3-hydroxy-1-propylpropyl]-L-cysteine 4 by Michael-addition of enantiomerically pure L-cysteine to (2E)-2-hexenoic acid ethyl ester followed by selective reduction of the ester function with sodium trimethoxyborohydride. All compounds were obtained as a diastereomeric mixture in good yields and their structures were determined by NMR and MS analyses.