Butanedione → 3-Hydroxy-3-phenylbutan-2-one

Participants

Reaction Steps

The process can also be run in mixtures of tetrahydrofuran and toluene, thereby making the process more economical. When 1.1 equivalent of phenylmagnesium bromide (1.9M in 50% THF/PhMe) was added to 2,3-butanedione in 50% THF/PhMe, crude product was isolated in 82.4% yield (Run 10, Table IV) after work-up. Short path vacuum distillation gave 3-hydroxy-3-phenylbutan-2-one in 68% yield. Alternatively, preparation of phenylmagnesium bromide in 38% THF/PhMe, followed by reaction with 2,3-butanedione in 38% THF/PhMe afforded 3-hydroxy-3-phenylbutan-2-one in 66.4% yield (Run 11, Table IV) after work-up and distillation. Similarly phenylmagnessium bromide in 25% THR/PheMe reacted with 2,3-butanedione in 25% THF/PheMe yielded 3-hydroxy-3-phenylbutan-2-one in 56.9% yield after work-up and distillation.

Provenance & Evidence