β-Lactams as building blocks in the synthesis of macrocyclic spermine and spermidine alkaloids
作者:Harry H Wasserman、Haruo Matsuyama、Ralph P Robinson
DOI:10.1016/s0040-4020(02)00731-7
日期:2002.8
Syntheses of the macrocyclicspermidinealkaloids (±)-celacinnine (1) and (±)-dihydroperiphylline (2) as well as the related spermine alkaloid (±)-verbascenine (3) were accomplished by means of sequential ring expansions of smaller lactam rings. Three ring expansion methods were employed: (1) transamidation of N-(aminoalkyl)lactams, (2) β-lactam-lactim ether condensation followed by reductive cleavage