Diastereo-and enantioselective carbonyl-ene reaction of glyoxylate (2) with t&substituted olefins (3) catalyzed by chiral titanium complexes (la), derived from 6,6'-dibromo-<,l'-bi-2-naphthol and diisopropoxylitanium dihaliies. is found lo provide syn-diastereomers exclusively along with a hih Mel of Recently, much attention has been paid to the development of asymmetric catalysis, particularly of carbon-carbon bond forming reaction .1 Among others, catalytic stereocontrol not only in absolute sense but also in relative sense is one of the most challenging and formidable endeavor in organic synthesis. We now wish to report herein the diastereoselective and enantioselective carbonyl-ene reaction2 of glyoxylate (2) with trisubstituted olefins (3) catalyzed by modified binaphthyl-derived chiral titanium dihalide complexes (la and b) (eq l), which provides an efficient access to the asymmetric synthesis of a-hydroxy-&methyl esters. (e-1 (X = Cl. Br) (10 mol%) O-C.2 h MS 4A L a&4 (11 We have previously reported that the binaphthol-derived chiral titanium complexes (lc) are quite effective for the enantioselective glyoxylate-ene reaction with 1 ,l -disubstituted olefins.3 Unfortunately however, the reaction with trisubstituted olefins (3) provides only a low to moderate