A new and effective method for the low temperature generation of sulfonium ylides from allyl sulfides

Abstract

Allyl 4-methoxyphenyl sulfides can be converted into sulphonium ylides which undergo [2,3] sigmatropic rearrangement in high yield and with excellent stereoselectivity by repeated alternate additions of a diazonium salt and tetrafluoroboric acid at low temperature. Under these conditions, side reactions are suppressed and both cyclic and open-chain compounds, including one containing a tertiary amine, give homoallylic sulfides in good yield. Epoxides may be made from the products.