Enantioselective aldol condensation of O-silyldienolates derived from alkyl-substituted 2,2-dimethyl-[1,3]-dioxin-4-ones

Vinylogous aldol condensation of masked alkylated acetoacetates proceeds with good to excellent yields and enantiomeric excesses in the presence of a chiral Ti(O-i-Pr)(4)/BINOL complex. The presence of positive nonlinear effects are also pointed out. (C) 2004 Elsevier Ltd. All rights reserved.