Use of an acetylenic sulfone as an alkene dipole equivalent in the total synthesis of (+,-)-pumiliotoxin C

cetylenic sulfones are versatile synthetic reagents that can undergo one or more conjugate additions at the ;Based on this behaviour, the synthesis of (;Thus, 1-(p-toluenesulfonyl)-1-pentyne underwent Michael addition with the free primary amine, methyl cis-2-amino-trans-6-methylcyclohexanecarboxylate, to furnish the corresponding enamine as a mixture of (E)- and (Z)-isomers in 93% yield. Intramolecular...