反应详情

A solution of 3,4-Dihydro-2H-pyran (24.7 g) was added drop wise at room temperature to a solution of 4[(6-hydroxyhexyl)oxy]benzoic acid (35 g), toluene-4-sulfonic acid monohydrate (1.8) in diethylether (440 ml) and stirred at room temperature for 18 h. The resulting mixture was filtered over Hyflo Super Cel (FLUKA), organic solvents were removed in vacuum. The residue (60 g) was purified by column flash chromatography on silica gel using toluene/ethyl acetate (1:1) as eluent, to give after crystallisation from ethyl acetate/hexane (5:40) 4{[6(tetrahydro-2H-pyran-2-yloxy)hexyl]oxy}benzoic acid.

1. filtrationThe resulting mixture was filtered over Hyflo Super Cel (FLUKA), organic solvents
2. customwere removed in vacuum
3. customThe residue (60 g) was purified by column flash chromatography on silica gel
4. customto give
5. customafter crystallisation from ethyl acetate/hexane (5:40) 4{[6(tetrahydro-2H-pyran-2-yloxy)hexyl]oxy}benzoic acid