A convenient, novel synthesis of beta-ketosilanes based on (Z)-1-bromo-1-al
kenylboronate esters is developed. alpha-Bromo-(Z)-1-alkenylboronate esters
readily available using literature procedures smoothly undergo a reaction
with trimethylsilylmethyllithium in tetrahydrofuran to provide the correspo
nding 'ate' complexes. These 'ate' complexes will undergo intramolecular nu
cleophilic substitution reactions to afford the corresponding (E)-trisubsti
tuted olefins containing trimethylsilylmethyl moiety. The oxidation of thes
e intermediates with sodium acetate and hydrogen peroxide provides beta-ket
osilanes in good yields (63-75% yield). (C) 2000 Elsevier Science Ltd. All
rights reserved.