Diisopropylamine → Lithium diisopropylamide

Participants

Reaction Conditions

Reaction Steps

A solution of lithium diisopropyl amide was prepared from diisopropyl amine (2.24 ml) and n-butyllithium (6.4 ml, 2.5N) in THF (60 ml) and cooled to -70° C. Methyl 2-(2-bromoethyl)-6-(4-t-butyldimethylsiloxy-1,3-dihydro-6-methoxy-7-methyl-3-oxoisobenzofuran -5-yl)-4-methyl-hex-4-enoate (2.66 g) in THF (12 ml was added to the LDA solution over 2 min. The reaction mixture was stirred for 50 min at -65° C. to -50° C. and quenched in water. Extraction with ethyl acetate and flash chromatography (silica gel, 20-30% ethyl acetate/hexane) gave 1-[4-(4-t-butyldimethylsiloxy-1,3-dihydro-6-methoxy-7-methyl-3-oxoisobenzofuran -5-yl)-2-methyl-but-2-enyl] cyclopropane carboxylic acid methyl ester (1.34 g).

Provenance & Evidence