Addition of the aromatic α-oxo ketene cyclic dithioacetals with methallyl Grignard reagent afforded the carbinols 3 . Catalyzed by BF~3·Et~2O, carbinols 3 were converted to the corresponding aromatic ethers 4 when the reaction was performed in alcohols used. While catalyzed by silica gel, the β,γ-unsaturated aromatic ketones 6 were obtained from the decomposation of 3. Some effective factors to the substitution-cycloaromatization reaction, such the volum of R^1 and the structure of dithioacetal group, were examined.

Key words: DECOMPOSITION, CYCLIZATION, MERCAPTAL