Sodium borohydride → 4-Hydroxy-cyclopent-2-ene-1,2-dicarboxylic acid dimethyl ester

Participants

Reaction Steps

NaBH4 (0.66 g, 17.5 mmol) dissolved in MeOH (23 mL) was added to a cold solution (−30° C.) of the ketone 23a (3.18 g, 16.1 mmol). After nine minutes the excess of NaBH4 was destroyed by adding brine (80 mL). The mixture was concentrated and extracted with ethyl acetate (4×80 ml). The organic phases were dried, filtrated and concentrated which gave the title compound (3.0 g, 92%) as a yellow oil.

Provenance & Evidence