Thermochemistry and photochemistry of spiroketals derived from indan-2-one: Stepwise processes versus coarctate fragmentations

• Götz Bucher,
• Gernot Heitmann and
• Rainer Herges

Beilstein J. Org. Chem. 2013, 9, 1668–1676, doi:10.3762/bjoc.9.191

• stepwise mechanisms may compete. Keywords: coarctate reaction; fragmentation; matrix isolation; photolysis; pyrolysis; spiroketal; Introduction Pericyclic reactions, according to the original definition, are characterized by a cyclic array of bond making and bond breaking [1][2][3]. At each atom

• of 11.3 kcal/mol and a concerted mechanism. This is in agreement with the stereochemical rule that a coarctate reaction with eight (4n) electrons should proceed via a Möbius transition state, with the two terminating groups orthogonal with respect to each other. The orthogonal arrangement is provided