Dimethyl Sulfoxide → HCID 10740642, compound

Participants

Reaction Conditions

Reaction Steps

Trifluoroacetic anhydride (1.6 ml) in methylene chloride (3.6 ml) was added dropwise to dimethyl sulfoxide (1.05 ml) and CH2Cl2 (7.5 ml) under nitrogen over 5 minutes at -60° C. and stirred for 30 minutes. After addition of (±)-2-(4-tert-butyldimethylsilyloxy-1,3-dihydro-6-methoxy -7-methyl-3-oxoisobenzofuran-5-yl)-1-cyclopentenyl-1-hydroxyethane (2 g) in methylene chloride (6 ml) over 15 minutes, the mixture was warmed to -40° C. over 1 hour. Triethylamine (10 ml) was added at -70° C., the cooling bath was removed, and after reaching ambient temperature the solution was diluted with ethyl acetate, washed twice with saturated aqueous potassium dihydrogen phosphate, brine, dried and evaporated. The solid residue was chromatographed on silica gel with 7:1 hexane, eluting with ethyl acetate to afford cyclopentenyl (4-tert-butyldimethylsilyloxy-1,3-dihydro -6-methoxy-7-methyl-3-oxoisobenzofuran-5-ylmethyl)methanone (1.65 g).

Provenance & Evidence