反应详情

A 1M solution of ethylmagnesium bromide in THF (200 ml, 0.2 mol) was treated with 29 ml (0.2 mol) of a solution of 3,4,5,6-tetrahydro-2-(2-propynyloxy)-2H-pyran in toluene, while maintaining ambient temperature through use of a cool water bath. The resulting solution was stirred for 4 h and treated with 47 ml (0.28 mol) of a solution of triethylorthoformate in toluene, while maintaining ambient temperature with a cool water bath. The resulting solution was heated to 85° C. for 8 h, allowing the removal of THF by distillation. After being allowed to cool, the resulting solution was poured into 500 ml of ice-water containing 29 g of NH4OAc, extracted with two portions of ether, dried over K2CO3, and concentrated in vacuo. The residue was distilled at ca. 0.5 mm Hg pressure (b.p. 103°-108° C.) to provide 39.5 g (79%) of the desired compound. 1H NMR (CDCl3) δ 1.24 (t, J=7 Hz, 6 H), 1.5-1.9 (m, 6 H), 3.5-3.65 (m, 3 H), 3.7-3.9 (m, 3 H), 4.32 (AA', 2 H), 4.81 (m, 1 H), 5.31 (m, 1 H). Mass spectrum: (M+NH4)+ =260.

1. temperaturewhile maintaining ambient temperature with a cool water bath
2. temperatureThe resulting solution was heated to 85° C. for 8 h
3. customthe removal of THF
4. distillationby distillation
5. temperatureto cool
6. additionthe resulting solution was poured into 500 ml of ice-water containing 29 g of NH4OAc
7. extractionextracted with two portions of ether
8. dry with materialdried over K2CO3
9. concentrationconcentrated in vacuo
10. distillationThe residue was distilled at ca. 0.5 mm Hg pressure (b.p. 103°-108° C.)