반응 #87950

반응 방정식

sodium hydroxide

methyl 7-methoxymethyl-2H-chromene-8-carboxylate

Intermediate 9

methyl 7-methoxymethyl-2H-chromene-8-carboxylate

bromoform

ethyl acetate

→

methyl cis-(1aRS,7bSR)-1,1-dibromo-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

용매

brine

반응 조건

후처리

1. 1
   온도After cooling
2. 2
   추출The aqueous layer was further extracted with ethyl acetate
3. 3
   건조the combined organic layers were dried (MgSO4)
4. 4
   여과filtered
5. 5
   기타The filtrate was evaporated to dryness
6. 6
   기타the residue was purified by chromatography on silica
7. 7
   세척eluting with a mixture of TBME and cyclohexane with a gradient of 0-35%

실험 절차

Aqueous sodium hydroxide solution (50% w/v, 1.63 mL) was added slowly to a vigorously stirred mixture of methyl 7-methoxymethyl-2H-chromene-8-carboxylate (Intermediate 9, 0.875 g), benzyltriethylammonium chloride (0.173 g) and bromoform (15 mL). The resultant mixture was vigorously stirred and heated at 60° C. for 3 hours. After cooling, the mixture was poured into a mixture of brine and ethyl acetate. The aqueous layer was further extracted with ethyl acetate and the combined organic layers were dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of TBME and cyclohexane with a gradient of 0-35% to give methyl cis-(1aRS,7bSR)-1,1-dibromo-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (1.06 g) as a white solid.

출처