BENZOPYRANS - PART 38 - REACTIONS OF 4-OXO-4H-1-BENZOPYRAN-3-CARBALDEHYDE, 4-OXO-4H-1-BENZOPYRAN-3-CARBONITRILE AND 4-OXO-4H-1-BENZOPYRAN-3-CARBOXYLATE WITH CHLOROACETONE AND A NOTE ON THE STEREOCHEMISTRY OF BENZO[B]CYCLOPROPA[E]PYRANS
Ck. Ghosh et al., BENZOPYRANS - PART 38 - REACTIONS OF 4-OXO-4H-1-BENZOPYRAN-3-CARBALDEHYDE, 4-OXO-4H-1-BENZOPYRAN-3-CARBONITRILE AND 4-OXO-4H-1-BENZOPYRAN-3-CARBOXYLATE WITH CHLOROACETONE AND A NOTE ON THE STEREOCHEMISTRY OF BENZO[B]CYCLOPROPA[E]PYRANS, Journal of chemical research. Synopses, (4), 1998, pp. 178-179
The title benzopyranones 1-3 give the benzo[b]furan 7 and the benzo[b]
cyclopropa [e] pyrans 8 and 9 with chloroacetone in acetone containing
anhydrous potassium carbonate and a catalytic amount of potassium iod
ide but give the 1-benzopyranones 10, 11 and 14 in dichloromethane in
the presence of Brockman neutral alumina, respectively.