反应详情

A solution of 2-(6-benzyloxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2yl)ethyl 2-(3-fluoro4-phenyl-phenyl)propionate in ethyl acetate was treated with 10% palladium on charcoal (Aldrich, 0.5 g). The resulting mixture was hydrogenated on a Parr Apparatus [initial pressure 60 pounds/inch2 (psi)]. After 18 hours, the reaction mixture was filtered, and the resulting solution concentrated in vacuo. The residue was subjected to flash chromatography (silica gel, 2:8, v:v, ethyl acetate:hexane). Concentration of the appropriate fractions afforded a clear oil. Hexane was added to the oil and a white solid formed upon standing. The white solid was collected by filtration to afford 0.91 g (36% yield) of 2-(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2yl)ethyl 2-(3-fluoro4-phenyl-phenyl)propionate as a mixture of stereoisomers.

1. filtrationthe reaction mixture was filtered
2. concentrationthe resulting solution concentrated in vacuo
3. customConcentration of the appropriate fractions afforded a clear oil
4. customa white solid formed
5. filtrationThe white solid was collected by filtration