ADDITION-REACTION OF PHOTOENOLS FROM O-METHYL-SUBSTITUTED AROMATIC KETONES WITH 5-ALKYLIDENE-1,3-DIOXANE-4,6-DIONE DERIVATIVES

Photolyses of 2-methylacetophenone or 2-methylbenzophenone with isobut ylidene Meldrum's acid or 5-isobutylidene-1,3-dioxane-4,6-dione deriva tives produced novel adducts, bonding between the beta-carbon of the a cylals and the 2-methyl carbon of the aromatic ketones. However, the p hotoenol derived from benzocyclobutenols by thermolysis did not underg o the addition reaction with the acylal. The benzocyclobutenols reacte d with isobutenylketene derived by pyrolysis of isobutylidene Meldrum' s acid to yield corresponding benzocyclobutenyl 4-methyl-3-pentenoate derivatives.