反应详情

A mixture of (1RS,4SR,5RS)-4-(4-carboxypentyl)-4-methyl-3,8-dioxabicyclo[3.2.1]octane-1-ethanol (58 mg, 0.2 mM), lithium hydride (10 mg, 1.25 mM) and ether (5 ml) is stirred at room temperature under nitrogen for two hours. An excess of 3-methyl-2-butenyl lithium is added to this mixture at room temperature. The resulting mixture is stirred for two hours and then treated with 5% sodium bicarbonate solution (5 ml) and extracted with ethyl acetate (3×20 ml). The combined organic layers are dried (Na2SO4), evaporated in vacuo and the residue is purified by column chromatography on silica gel (7 g) with ether to give (1RS,4SR,5RS)-4-(4,8-dimethyl-5-oxo-7-nonenyl)-4-methyl-3,8-dioxabicyclo[3.2.1]octane-1-ethanol (13 mg), 25%) as a colorless oil).

1. stirringThe resulting mixture is stirred for two hours
2. extractionextracted with ethyl acetate (3×20 ml)
3. dry with materialThe combined organic layers are dried (Na2SO4)
4. customevaporated in vacuo
5. customthe residue is purified by column chromatography on silica gel (7 g) with ether