TERT-BUTYL TRIMETHYLSILYLACETATE

Physical properties

air stable, colorless liquid; bp 67°C/13 mmHg; n20 D 1.4184; 1H NMR (CDCl3, 90 MHz) 0.13 (s, 9H), 1.45 (s, 9H), 1.80 (s, 2H); IR 1710 cm?1.

The Uses of TERT-BUTYL TRIMETHYLSILYLACETATE

t-Butyl Trimethylsilylacetate is used to prepare lithium enolates which can be alkylated;can be alkenated with aldehydes and ketones;can be acylated;can be reacted with Group 14 halides.
Most applications require initial formation of the enolate (1) (eq 1), which is obtained as a white solid suspended in THF, stable indefinitely at ?78°C.

Preparation

an advantage of t-butyl trimethylsilylacetate over its methyl and ethyl ester analogs is that it can be prepared by C-silylation of the lithium enolate of t-butyl acetate at ?78°C in THF (85–90% yield). Under the same conditions the enolates of methyl and ethyl acetate give primarily O-silylated products.The reagent has also been prepared by a rapid boron trifluoride etherate catalyzed reaction of trimethylsilylketene with t-butyl alcohol.