Several a-silyl selenides (2, 10) have been prepared by silylation of a-lithio selenides and alkylation of a-lithioa-silyl selenides. Oxidation of these selenides to selenoxides results in competitive selenoxide syn elimination to give vinyl silanes (4) and sila-Pummerer rearrangement to give vinyl selenides (8) and carbonyl compounds. The ratio can be controlled to some extent by control of reaction conditions, but a more pronounced change ...