Double Lawton S_N2‘Addition to Epoxyvinyl Sulfones:  Selective Construction of the Stereotetrads of Aplyronine A

Abstract

[reaction: see text] Enantiopure epoxyvinyl sulfones function as templates for the diastereoselective construction of the three stereotetrads of aplyronine A. Lawton S(N)2' addition of 3,5-dimethylpyrazole followed by its displacement in an alcohol-directed Lawton S(N)2' reaction establishes the required product stereochemistry with high selectivity.