Synthesis of polymeric chiral L-prolinol derivatives and its applications on the asymmetric Michael addition

N-acylation Of L-prolinol (2) with enoyl chloride provided L-cinnamoylproli nol (3a) and L-crotonylprolinol (3b), respectively. The attachment of (3a) or (3b) to Merrifield resin and the utilization of such a system for asymme tric Michael additions of Grignard reagents to alpha, beta -unsaturated car bonyl compounds were studied. The stereoselectivities have been increased c ompared with those observed for the same reactions in solution. On the othe r hand, it has been proved by the FT-IR difference spectrum of the Merrifie ld resin and polymer-supported chiral auxiliary that L-prolinol derivatives have been coupled to the resin. (C) 2001 Elsevier Science B.V. All rights reserved.