assembled from a phosphonate corresponding to the C8–C15 segment (prepared from l-malic acid in 19 steps) and an aldehyde corresponding to the C16–C20 segment (synthesized from 3-methyl-3-butenol in nine steps) by a twelve-step process including the Horner–Wadsworth–Emmons reaction, regio- and stereoselective reduction of the resulting enone, diastereoselective epoxidation, and 5-exo epoxide cleavage