Abstract
Active methylene compounds, diethyl malonate, α-tetralone, dimedone, acetyl-acetone, malononitrile, and diketene, were reacted with 1-ethoxyisochroman (1) to give the corresponding 1-substituted isochroman derivatives, 4, 5, 6, 7, 8, 9, 10, and 11, respectively. When 4 was treated with sodium ethoxide or potassium tert-butoxide, ethyl 1, 4-dihydro-2-naphthoate (14a), ethyl 1, 2-dihydro-2-naphthoate (14b), and ethyl 2-naphthoate (13) were obtained. On the other hand, the reaction of 2-(1-isochromanyl) cyclohexanone (3) with potassium tert-butoxide afforded 9-formyl-1, 2, 3, 4-tetrahydroanthracene (20) and 1, 2, 3, 4, 9, 10-hexahydroanthracene (21). The conversion mechanisms of 1-substituted isochromans (2, 3, 4, and 7) into naphthalenes (13, 14a, b, and 18) and 1, 2, 3, 4-tetrahydroanthracenes (20 and 21) are proposed.
