Enantioselective total synthesis of (R)-strongylodiols A and B

We describe an expeditious enantioselective total synthesis of the acetylenic marine natural products (R)-strongylodiols A and B. Central to the strategy is the use of Zn(OTf)2, amine base, and N-methyl ephedrine to mediate the direct addition of a 1,3-diyne to two long-chain aliphatic aldehydes in useful selectivities and yields.