Synthesis of 2,3-dihydro-6H-1-oxa-3a-aza-phenalene and its benzo/hetero-fused analog
A simple and efficient method for the synthesis of highly substituted benzo- and hetero-fused analog of 2, 3-dihydro-6H-oxa-3a-aza-phenalene was developed using 2H-1, 4-benzoxazine and α-oxoketene dithio-acetals.