Studies directed toward the design of chiral acylating agents. The utility of chiral N-benzoylimides in enantioselective alcohol acylation
摘要:
N-benzoyl-4(S)-tert-butyl-2-oxazolidinone (1b) is found to be an efficient enantioselective acylating agent for aryl n-alkyl carbinols. Selective benzoylation of racemic aryl n-alkyl carbinols with kinetic selectivities of 20-30:1 for the (R) enantiomer is observed. The acylation process is promoted by formation of the derived magnesium alkoxides which may be accessed either from alcohol deprotonation with MeMgBr or through deprotonation with the Lewis acid-base combination of MgBr2/R3N.