Use of an Acetylenic Sulfone as an Alkene Dipole Equivalent in the Synthesis of (.+‐.)‐Pumiliotoxin C.

Abstract The cycloaddition of methyl cis -2-amino- trans -6-methylcyclohexanecarboxylate ( 3 ) with 1-p-(toluenesulfonyl)-1-pentyne ( 4 ) afforded the corresponding enaminone 2 , that was in turn reduced to (±)-pumiliotoxin C ( 1 ). The acetylenic sulfone 4 thus functions as the synthetic equivalent of the alkene dipole 5 in this process.