TRANSFORMATION OF ALPHA-ASSISTED CARBANIONS INTO THE CORRESPONDING TRIMETHYLSILOXY DERIVATIVES USING BIS(TRIMETHYLSILYL) PEROXIDE

The reaction of bis(trimethylsilyl)peroxide with tlithium derivatives of sulphides and nitriles is reported to give the corresponding O-trimethylsilyl hemithioacetals and cyanohydrins. From these products the carbonyl function can be exposed in acidic media or in the presence of fluoride ions. This methodology provides an attractive route to transform a CH2-X group (X = PhS, MeS or CN) into the corresponding CHO, allowing the preparation of aldehydes that can be considered difficult to prepare such as, for example, formyltrimethylsilane which was generated and trapped in situ using a Wittig reaction. © 1990.