Reaction of 2, 2-Dimethyl-1, 3-dioxin-4-one Derivatives with Pyridinium (Isoquinolinium) Methylides and Cyano Compounds

Abstract

Cycloaddition of acylketenes (2) to 1, 2-and 1, 3-dipolar compounds was investigated. The thermal reaction of 1, 3-dioxin-4-ones (1) with isoquinolinium phenacylide (11) gave the aromatized pyrrolo [2, 1-a] isoquinolines (12-15). The reaction of 1 with pyridinium and isoquinolinium cyanomethylides (3-5) afforded the 1, 3-oxazinylmethylides (6-8). The intermediate 2 likewise reacted with cyanamides and benzonitriles to give the corresponding 1, 3-oxazin-4-one derivatives (19-23).