Water → (1S,2R)-2-(4-chlorophenyl)-1'-(2,2-dimethoxyethyl)spiro[cyclopropane-1,3'-indolin]-2'-one

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Reaction Conditions

Reaction Steps

To a solution of (1R,2S) and (1S,2R)-2-(4-chlorophenyl)spiro[cyclopropane-1,3′-indolin]-2′-one (135 mg, 1 mmol) in DMF (1 mL) was added KHMDS (0.5 M in THF, 1.1 mL) was dropwise at room temperature. The mixture was stirred for half an hour before adding bromoacetaldehyde dimethyl acetal (95 mg, 0.55 mmol). The mixture was warmed to 50° C. and stirred at that temperature for 2 hours. The mixture was poured into water, extracted with ethyl acetate (3×15 mL), dried and concentrated under reduced pressure. Purification by flash column chromatography on silica gel, eluting with hexanes-EtOAc (6:1 and then 4:1) gave the desire product as colorless oil (268 mg, 75%). LC/MS m/e calcd. for C20H20ClNO3: 3570, observed (M+H)+: 358.7.

Provenance & Evidence