STUDIES TOWARD THE SYNTHESIS OF (-PALUSTRINE - THE FIRST ASYMMETRIC-SYNTHESIS OF (-)-METHYL PALUSTRAMATE())

The stereoselective synthesis of(-)-methyl palustramate, a possible in termediate for the synthesis of(+)-palustrine, is described. The key s tep of the synthesis is a conformationally restricted Claisen rearrang ement to afford the highly functionalized 1-benzylpipecolic ester 10. In addition, a new procedure for debenzylation of 1-benzylpiperidines (Li, (NH2CH2)(2), Et3N, THF) was used to remove the benzyl protecting group where traditional methods failed.