反应详情

A solution of 2-[[(4S,5R)-5-[(1E,3E)-1,3-hexadien-5-ynyl]-2,2-dimethyl-1,3-dioxolan-4-yl]methoxy]ethanoic acid in THF was cooled in an ice bath and treated with a solution of trimethylsilyldiazomethane in THF in portions. Excess diazomethane was decomposed with acetic acid and the mixture was diluted with ether and washed with water, saturated sodium bicarbonate, water (2×), and brine, dried, treated with silica gel and concentrated. Purification by chromatography on silica gel using a gradient of ether in hexane gave 0.9 g of 2-[[(4S,5R)-5-[(1E,3E)-1,3-hexadien-5-ynyl]-2,2-dimethyl-1,3-dioxolan-4-yl]methoxy]ethanoic acid, methyl ester, a compound of formula (W), as an oil: 1H NMR (CDCl3) δ1.37 (s, 3H), 1.51 (s, 3H), 3.06 (s, 1H), 3.49 (m, 2H), 3.74 (s, 3H), 4.16 (m, 2H), 4.42 (m, 1H), 4.65 (t, 1H), 5.60 (dd, 1H), 5.79 (dd, 1H), 6.33 (dd, 1H), 6.65 (dd, 1H) ppm.

1. washwashed with water, saturated sodium bicarbonate, water (2×), and brine
2. customdried
3. additiontreated with silica gel
4. concentrationconcentrated
5. customPurification by chromatography on silica gel using a gradient of ether in hexane