A concise total synthesis of brasiliquinones B and C and 3-deoxyrabelomycin

摘要

Synthesis of brasiliquinones B and C, 2 and 3 and 3-deoxyrabelomycin 4a has been accomplished in 6-7 steps from the common precursor 18b. The key naphthalenones 6 were prepared in 5 steps from tetralone 17 in a regioselective manner. Anionic annulation of cyanophthalide 7c with 6 readily provided tetracyclic precursors 5 in excellent yields, sunlight-promoted photooxidation of which led to the synthesis of the title compounds.