Diradical-Promoted Two-Carbon Ring-Expansion Reactions by Thermal Isomerization: Synthesis of Functionalized Macrocyclic Ketones
作者:Georg Rüedi、Hans-Jürgen Hansen
DOI:10.1002/hlca.200490150
日期:2004.7
of functionalized macrocyclic ketones has been developed. Pyrolysis of medium- and large-ring 3-vinylcycloalkanones by dynamic gas-phase thermo-isomerization (DGPTI) at 600–630° yielded, under insertion of a previously attached vinyl side chain by means of a 1,3-C shift, the corresponding γ,δ-unsaturated cycloalkanones. The yield of the two-carbon ring-expanded ketones greatly depended on the relative
A Novel and Highly Efficient Two-Carbon Ring Expansion
作者:Georg Rüedi、Matthias Nagel、Hans-Jürgen Hansen
DOI:10.1021/ol035700y
日期:2003.10.1
[reaction: see text]. Dynamic gas-phase thermoisomerization (DGPTI) of medium- and large-ring 3-vinylcycloalkanones at 600-630 degrees C produces isomeric gamma,delta-unsaturated cycloalkanones expanded by two carbon atoms. A reaction mechanism involving an open-chain diradical intermediate, followed by intramolecular recombination under insertion of the vinyl group is proposed. Substituents on the