Formal total synthesis of (+)-12-deoxyscalarolide
Abstract
An effective formal total synthesis of (+)-12-deoxyscalarolide is described, starting from natural manool. Two alternative reaction schemes have been investigated for the synthesis of the tetra-carbocyclic key intermediate (–)-methyl 17-oxo-24-norscalaran-25-oate. The unsaturated lactonic ring is then created from this ester in three steps to afford, in high yield, the (–)-scalar-16-en-25,24-olide which is easily isomerised under basic conditions to (+)-12-deoxyscalarolide.