Torquoselective Ring Closures of Chiral Amido Trienes Derived from Allenamides. A Tandem Allene Isomerization−Pericyclic Ring-Closure−Intramolecular Diels−Alder Cycloaddition

A new torquoselective ring-closure of chiral amide-substituted 1,3,5-hexatrienes and its application in tandem with [4 + 2] cycloaddition are described. The trienes were derived via either a 1,3-H or 1,3-H−1,7-H shift of α-substituted allenamides, and the entire sequence through the [4 + 2] cycloaddition could be in tandem from allenamides.