反应详情

A stirred mixture of ethyl 4-(3-bromophenyl)-3,4,5,6-tetrahydro-2H-pyran-4-carboxylate (36.5 g, 117 mmol), an aqueous solution of lithium hydroxide (6.14 g, 146 mmol, 50 ml), methanol (150 ml) and THF (150 ml) was refluxed for 1 day. The reaction mixture was partitioned between ether (100 ml) and 10% aqueous potasium hydroxide solutuion (300 ml). The ethereal layer was separated, extracted with 10% aqueous potasium hydroxide solutuion (2×100 ml) and discarded. The combined aqueous extracts were acidified with concentrated hydrogen chloride and the resulting white precipitates were collected by filtration, washed with water and dried to constant weight under vacuum at 80° C. to give the titled compound as white solids (26.4 g, 79%).

1. customThe reaction mixture was partitioned between ether (100 ml) and 10% aqueous potasium hydroxide solutuion (300 ml)
2. customThe ethereal layer was separated
3. extractionextracted with 10% aqueous potasium hydroxide solutuion (2×100 ml)
4. customthe resulting white precipitates
5. filtrationwere collected by filtration
6. washwashed with water
7. customdried to constant weight under vacuum at 80° C.