FUROPYRIDINES .19. REACTION OF FURO[2,3-B]PYRIDINE, FURO[3,2-B]PYRIDINE, FURO[2,3-C]PYRIDINE AND FURO[3,2-C]PYRIDINE WITH ACETIC-ANHYDRIDE

Acetoxylation of N-oxide of furo[2,3-b]- 2a, -[3,2-b]-2b, -[2,3-c]- 2c and -[3,2-c]pyridine 2d with acetic anhydride afforded compounds subs tituted normally at the alpha- or gamma-position to the ring nitrogen, 3a, 4a, 4b, 3d, 4d, 8 and 9, and in addition compounds substituted on the furan ring, 5a, 6a, 5b, 6b, 7b, 5c and 7c which were unexpected c ompounds. The structures of these compounds were established from the ir, nmr and mass spectra, and x-ray crystal analysis of 5b.