Examination of a proposed reaction scheme to prepare bicyclo-(2.2.0)hexan-1-ol produced the first known condensation of an
enamine with its carbonyl precursor. Hydrolysis of the resulting
dienamine gave an unusual conjugated cyclobutenone in which the
double bond is exocyclic. Characterization and reactions of the
cyclobutenone were successfully carried out.
Cyclopropylcyclobutene was prepared via the intermediate
dicyclopropylcarbinyl carbene which was generated by the thermal
decomposition of the sodium salt of dicyclopropylketone p-toluenesulfonylhydrazone.
The successive thermal isomerization of cyclopropylcyclobutene
to 2-cyclopropyl-1, 3-butadiene and to vinylcyclopentene
was studied. Kinetic data were obtained for the cyclopropylcyclobutene
to 2-cyclopropyl-1, 3-butadiene isomerization in the gas...