Treatment of homoallylic alcohols or carboxylic acids with malonoyl peroxide 1 provides a stereoselective method for the preparation of tetrahydrofurans, ɣ-lactones and isobenzofuranones in 44–82% yield and up to 27:1 trans-selectivity. Application of this simple and effective heterocyclization in the synthesis of the antidepressant citalopram is also described.
- saturated oxygen heterocycles
- homoallylic alcohols
- carboxylic acids