T. Liao, P. J. Wittek, C. Cheng
Dec 1, 1976
Citations
0
Influential Citations
23
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Partial mclhylalion of gallopropiophenonc (4) followed by benzylation and base-catalyzed condensation with ethyl acetate yielded 3-(2-benzyloxy-3,4-din]etlK>xy)benzoyl-2-butanonc (6). Animation of the latter and subsequent base-catalyzed cyclization with ethyl cyanoacetate gave 4-(2-benzyloxy-3,4-dimethoxy)phenyl-5,6-dimethyl-2-oxo-1,2-dihydropyridine (8). Removal of the 2-oxo group of 8 through chlorination and dechlorination and stepwise conversion of the 5-cyano and 2-methyl groups into the 5-amino and 2-carboxylic acid groups, respectively, with introduction and removal of protecting groups at proper stages, yielded the C-D ring moiety of the antitumor antibiotic streptonigrin.