Synthesis of O‐Benzyl Protected anti Aldols Through the Cross‐Coupling Reaction of Dibenzyl Acetals with a Chiral Titanium Enolate.

Abstract

AlcoholsAlcohols P 0110 Synthesis of O-Benzyl Protected anti Aldols Through the Cross-Coupling Reaction of Dibenzyl Acetals with a Chiral Titanium Enolate. -The titanium enolate derived from amide (I) reacts with acetals (II) in the presence of SnCl4 with good diastereoselectivity. This result is further improved with acetal (V) providing the Felkin type diastereomer (VI) exclusively. Removal of the chiral auxiliary under different reaction conditions gives access to a variety of building blocks (VII), (VIII) and (X). -(COSP, A.; LARROSA, I.; VILASIS, I.; ROMEA*, P.; URPI*, F.; VILARRASA, J.; Synlett 2003, 8, 1109-1112; Dep. Quim. Org., Univ. Barcelona, E-08028 Barcelona, Spain; Eng.) -Mais 41-075