Studies in polypropionate synthesis: High π-face selectivity in Syn and Anti aldol reactions of chiral boron enolates of lactate-derived ketones

Article abstract of DOI:10.1016/0040-4039(94)88434-X

Use of (c)Hex₂Bcl/Me₂NEt in the aldol reactions of the α'-benzoyloxy ketone 7 with aldehydes leads to high stereoselectivity (97-95.5% ds) for the crystalline anti adducts 11. Under similar conditions, the corresponding benzyl ether 6 favours formation of the syn adducts 9.