Ethyl isobutyrate → ethyl (E)-6-(1,3-dihydro-4-methoxyethoxymethoxy-6-methoxy-7-methyl-3-oxoisobenzofuran-5-yl)-2,2,4-trimethyl-3-hydroxy-4-hexenoate

Participants

Reaction Conditions

Reaction Steps

Freshly distilled diisopropylamine (0.425 ml) was dissolved in anhydrous THF (10 ml) and cooled to 0° C. n-BuLi (0.63 ml, 2.35M) was added slowly and the reaction was stirred at 0° C. for 20 minutes and cooled to -78°. Ethyl isobutyrate (0.200 ml) was added and the resulting solution was stirred at -78° C. for 40 minutes. A solution of (E)-4-(1,3-dihydro-6-methoxy -4-methoxyethoxymethoxy-7-methyl-3-oxoisobenzofuran-5-yl) -2-methylbut-2-enaldehyde (365 mg) in THF (10 ml) was added and stirred for 30 min. The reaction mixture was poured to a concentrated solution of NH4Cl, and extracted with ethyl acetate (3×30 ml), the organic layers were dried over Na2SO4, and evaporated to give 420 mg (87%) of ethyl (E)-6-(1,3-dihydro-4-methoxyethoxymethoxy-6-methoxy-7-methyl-3-oxoisobenzofuran-5-yl) -2,2,4-trimethyl-3-hydroxy-4-hexenoate as an oil.

Provenance & Evidence