Acetylene → HCID 13135222, compound

Participants

Reaction Steps

Acetylene, purified by passing it first through a dry ice acetone trap, then through concentrated sulfuric acid, was bubbled rapidly through freshly distilled tetrahydrofuran (20 ml) under nitrogen for one hour. Ethylmagnesium bromide (50 ml, 3.15 M in ether, 15.8 mmole) was added slowly. The temperature was maintained between 28°-33° C. by cooling with a water bath. After the complete addition of ethylmagnesium bromide, the passage of the acetylene gas was continued and 1,4-dimethoxy-6-tetralone (XIII) (1.03 g, 5 mmole) in dry tetrahydrofuran (5,0 ml) was added with stirring. After addition, the passage of the acetylene was continued for an extra one hour and the reaction mixture was left stirring at room temperature overnight. The reaction mixture was quenched with saturated oxalic acid and extracted with chloroform. The chloroform extract was washed well with water, dried over anhydrous magnesium sulfate, and evaporated to dryness. The oil residue was triturated with ether to give 1,4-dimethoxy-6-ethynyl-6-hydroxy-5,8-dihydro-(7H)naphthalene (XIV) as a white solid, m.p. 103°-105° C. (ethanol).

Provenance & Evidence