Tetrahedron

Total synthesis of c 19-diterpene alkaloids: construction of a functionalized bcd-ring system

…, JL Van Der Baan, GW Klumpp, F Bickelhaupt

Index: Beek, G. van; Baan, J. L. van der; Klumpp, G. W.; Bickelhaupt, F. Tetrahedron, 1986 , vol. 42, # 18 p. 5111 - 5122

Full Text: HTML

Citation Number: 13

Abstract

The construction of the BCD-ring system of C19-diterpene alkaloids was initiated by development of a ring expansion reaction of cyclic enamino-esters with propiolic acid esters, leading from the 5-membered ring ketone 3 to the 7-membered ring ketone 10. Epoxidation and stereospecific reductive epoxide ring opening to give hydroxy ester 18 were subsequent key-steps which eventually furnished cyclic β-keto ester 22. This versatile intermediate ...