Benzoin → HCID 10927656, compound

Participants

Reaction Steps

A methylene chloride solution (20 ml) of (-)-5(S)-(3-methoxybenzyl)-1-cyclopentenecarboxylic acid (1.99 g), thionyl chloride (2 ml) and N,N-dimethylformamide (2 drops) was stirred for 3 hours at room temperature. Removal of solvent at reduced pressure afforded the crude acid chloride as a brown oil. To a methylene chloride solution (20 ml) of the crude acid chloride and benzoin (1.97 g), pyridine (2 ml) was added at room temperature. The solution was stirred for 4 hours at the same temperature and washed with IN hydrochloric acid (×2) and brine. Drying (sodium sulfate) and removal of solvent afforded a yellow oil. An acetic acid solution (80 ml) of the yellow oil and ammonium acetate (14.98 g) was stirred for 7.5 hours at 130° C. and cooled to room temperature. Solvent was removed and the residue was dissolved in ethyl acetate. The solution was washed with water, saturated aqueous sodium hydrogen carbonate (×3), water, and brine. Drying (sodium sulfate) and removal of solvent at reduced pressure followed by flash chromatography on 100 g of silica afforded (+)-1-(4,5-diphenyloxazol-2-yl)-5(S)-(3-methoxybenzyl)cyclopentene as a pale yellow solid (2.69 g, 99.6% ee).

Provenance & Evidence