반응 #82210

반응 방정식

ethylmagnesium bromide

THF

3,4,5,6-tetrahydro-2-(2-propynyloxy)-2H-pyran

triethylorthoformate

→

desired compound

수율 79.0%

1,1 -Diethoxy-4-((3,4,5,6-tetrahydro-2H-pyran-2-yl)oxy)-2-butyne

수율 79.0%

용매

toluene

toluene

반응 조건

후처리

1. 1
   온도while maintaining ambient temperature with a cool water bath
2. 2
   온도The resulting solution was heated to 85° C. for 8 h
3. 3
   기타the removal of THF
4. 4
   workup.DISTILLATIONby distillation
5. 5
   온도to cool
6. 6
   workup.ADDITIONthe resulting solution was poured into 500 ml of ice-water containing 29 g of NH4OAc
7. 7
   추출extracted with two portions of ether
8. 8
   건조dried over K2CO3
9. 9
   농축concentrated in vacuo
10. 10
    workup.DISTILLATIONThe residue was distilled at ca. 0.5 mm Hg pressure (b.p. 103°-108° C.)

실험 절차

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.

출처