methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-2-oxoacetate → methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-2-hydroxypropanoate

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, a solution of methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-2-oxoacetate (360 mg, 1.09 mmol) in anhydrous diethyl ether (5 mL) was cooled to 0° C. Methyl magnesium bromide 3.0 M in diethyl ether (0.73 mL, 2.18 mmol) was added dropwise and the reaction mixture was stirred at 0° C. for 15 minutes, before being quenched with a minimum of water. Ethyl acetate (8 mL) was added and the mixture was dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 100/0 to 80/20) to provide the desired alcohol (42b) (206 mg, 0.59 mmol, 55%) as a colorless oil.

Provenance & Evidence