A route to the structure proposed for puetuberosanol and approaches to the natural products marshrin and phebalosin

Synthesis of the structure claimed for puetuberosanol (using the Juliá–Colonna oxidation in a key step) showed that the natural product was a different material. The isomeric epoxy alcohols can be discounted from the alternatives. An analogue of marshrin was prepared but the synthesis of the natural product was thwarted by failure of a Juliá–Colonna oxidation in the key step. The epoxy ketone was prepared by Darzens condensation and was converted into (±)-phebalosin .