反应详情

A mixture of (1RS,4SR,5RS)-4-(4-carbomethoxypentyl)-4-methyl-3,8-dioxabicyclo[3.2.1]octane-1-ethanol (71 mg, 0.24 mM), methanol (3 ml), water (1 ml) and 1 N sodium hydroxide (1 ml) is stirred at room temperature under nitrogen for twenty hours. Most of the methanol is removed in vacuo and the residue is treated with concentrated hydrochloric acid (1 ml) at 0° C. and extracted with ethyl acetate (3×30 ml). The combined organic layers are dried (Na2SO4) and evaporated in vacuo to give a colorless oil. This material is filtered through a silica gel column (3 g) and washed with ether (200 ml). The solvent is removed in vacuo to give (1RS,4SR,5RS)-4-(4-carboxypentyl)-4-methyl-3,8-dioxabicyclo[3.2.1]octane-1-ethanol (58 mg, 88%) as a colorless oil.

1. customMost of the methanol is removed in vacuo
2. additionthe residue is treated with concentrated hydrochloric acid (1 ml) at 0° C.
3. extractionextracted with ethyl acetate (3×30 ml)
4. dry with materialThe combined organic layers are dried (Na2SO4)
5. customevaporated in vacuo
6. customto give a colorless oil
7. filtrationThis material is filtered through a silica gel column (3 g)
8. washwashed with ether (200 ml)
9. customThe solvent is removed in vacuo