Frank Cooke

Silicon in synthesis—17 : Chloromethyl(trimethylsilyl)lithium—anew reagent for the direct conversion of aldehydes and ketones into ⇌,β,-epoxytrimethylsilanes

Abstract Treatment of chloromethyltrimethylsilane 1 with sec-BuLi in THF at -78° produces chloromethyl(tri-methylsilyl)lithium 4. Treatment of 4 with a wide range of aldehydes and ketones gives ⇌,β-epoxytrimethylsilanes 5–28, which on acidic hydrolysis give homologated aldehydes.

Silicon in synthesis. C2-C3 annulation using vinyltrimethylsilane as an ethylene equivalent for bicyclo[n.3.0]enone synthesis

Vinyltrimethylsilane reacts with cyclic α,β-unsaturated acid chlorides in the presence of stannic tetrachloride to give bicyclo[n.3.0]enones.

Intermolecular and intramolecular alkylation of mono- and di-anions derived from a β-ketosulphone

Alkylation of the 1,3-dianion of the β-ketosulphone (1) with 1,3-dibromopropane gave (3) which under appropriate conditions can be converted into either (6; C-alkylation) or (7; O-alkylation) without contamination with the other C- or O-alkylated isomer.

Organosilicon chemistry in synthesis: silylcyclopropanation

αβ-Unsaturated ketones have been shown to react with trimethylsilylmethylene-sulphurane (2; X = SMe2) to give silycyclopropyl ketones.