Patent ID: 7049440

Claim:
An enantioselective process of preparing a compound represented by formula VI wherein R 1 is H or a protecting group; which comprises contacting a compound represented by formula V in an inert organic solvent with at least about an equivalent amount of each of: (i) a chiral amino alcohol represented by the formula XI wherein R is an aryl, akylaryl, alkoxylary, arylaryl, heteroaryl, or polycyclic aryl group, or formula XII wherein in formula XII, the dotted line represents an optional second bond and wherein R 2 is selected from alkoxy, alkoxyalkyoxy, aryloxy, arylalkoxy, and NR A R B , wherein R A and R B are independently alkyl or aryl, and R 2 is optionally substituted by one or more alkoxy groups; (ii) a compound represented by formula X wherein LG is a leaving group, and said leaving group is a sulfonate, and R 1 is H or a protecting group; and (iii) an organic ether or amine additive, wherein the organic ether or amine additive is 2-isopropylamine, tetramethylethylenediamine or N-ethylaniline, N-phenyl, N-benzylamine or N-phenyl, 1-or 2-naphthyl amine or mixtures thereof to form a reaction mixture; then adding to the reaction mixture at least an equivalent amount of a non-nucleophilic strong base in an organic solvent, wherein the non-nucleophilic strong base is a lithium base selected from the group consisting of lithium diisopropyl amide, lithium N-butyl-N-phenyl amide, lithium bis(trimethylsilyl)amide, and lithium N-ethyl, N-phenyl amide, and optionally adding an equivalent amount of water or a C 1 –C 3 alcohol to produce the compound represented by formula VI.