Asymmetric synthesis of either enantiomer of opium alkaloids and morphinans. Total synthesis of (-)-and (+)-dihydrocodeinone and (-)-and (+)-morphine

CY Hong, N Kado, LE Overman

Index: Hong, Chang Y.; Kado, Noriyuki; Overman, Larry E. Journal of the American Chemical Society, 1993 , vol. 115, # 23 p. 11028 - 11029

Full Text: HTML

Citation Number: 175

Abstract

Our strategy was to first form an enantioenriched octahydroisoquinoline* and then employ an intramolecular Heck reaction to forge the critical quaternary center of the morphinan skeleton. 93'0 The synthesis of the (R)-allylsilane amine 9, the precursor of natural morphine, is summarized in Scheme I. Enantioselective reductionll of 2-allylcyclohex-2-en-1- one (5) 12 with catecholborane in the presence of the (R)-oxazaborolidine catalyst 613