Highly Stereoselective Aldol Condensation Using an Enantioselective Chiral Enolate

The 3,4-stereochemistry of aldol adducts can now be controlled for the first time with the new, chiral, readily accessible enolate reagent (2); i.e. the chiral aldehyde (1) can be transformed both into 3,4-anti- and into the 3,4-syn-aldol adduct, (3) and (4), as major product. (2a) forms (3a) and (4a) in the ratio of 15:1, while (2b) leads to (3b) and (4b) in the ratio of 1:10.