Experimental evidence of a cyclopropylcarbinyl conjugative electronic effect.

Bicyclo[3.2.0]hept-2-enes undergo thermal rearrangement to norbornenes via diradical transition structures.

A vinylcyclobutane substrate designed as a cyclopropylcarbinyl radical probe.

Appending a spirocyclopropane linkage to bicyclo[3.2.0]hept-2-ene is achieved by selective kinetic cyclopropanation of 6-methylenebicyclo[3.

Thermal isomerizations of cis,anti,cis-tricyclo[7.4.0.0(2,8)]tridec-10-ene.

cis,anti,cis-Tricyclo[7.4.0.

Molecular rearrangements through thermal [1,3] carbon shifts.

Molecular rearrangements through thermal [1,3] carbon shifts, such as vinylcyclopropane-to-cyclopentene and vinylcyclobutane-to-cyclohexene isomerizations, were recognized and exemplified repeatedly from 1960-1964. Serious mechanistic studies of these and related rearrangements over the past 40 years have provided ample grounds for interpreting them as processes taking place by way of conformationally flexible but not statistically equilibrated diradical intermediates. Orbital symmetry theory fails to account for the stereochemical characteristics of [1,3] carbon shifts.

Effect of a methoxy substituent on the vinylcyclobutane carbon migration.

Over the temperature range 250-300 degrees C, 8-exo-methoxybicyclo[4.2.0]oct-2-ene (1a) undergoes a [1,3] sigmatropic rearrangement to 5-exo- and 5-endo-methoxybicyclo[2.

Thermal chemistry of bicyclo[4.2.0]oct-2-enes.

At 300 degrees C, bicyclo[4.2.0]oct-2-ene (1) isomerizes to bicyclo[2.

Thermal reactions of 7-d- and 8-d-bicyclo[4.2.0]oct-2-enes.

The gas phase thermal reactions exhibited by bicyclo[4.2.0]oct-2-ene and 7-d and 8-d analogues at 300 degrees C have been followed kinetically through GC and 2H NMR spectroscopic analyses.

Thermal isomerization of cis,anti,cis-tricyclo[6.3.0.0(2,7)]undec-3-ene to endo-tricyclo[5.2.2.0(2,6)]undec-8-ene.

[reaction: see text] The gas-phase thermal isomerization of cis,anti,cis-tricyclo[6.3.0.

Thermal reactions of 8-methylbicyclo[4.2.0]oct-2-enes: competitive diradical-mediated [1,3] sigmatropic, stereomutation, and fragmentation processes.

[reaction: see text] At 275 degrees C, 8-exo-methylbicyclo[4.2.0]oct-2-ene (1a) undergoes a [1,3] sigmatropic rearrangement to 5-methylbicyclo[2.

Deuterium kinetic isotope effects and mechanism of the thermal isomerization of bicyclo[4.2.0]oct-7-ene to 1,3-cyclooctadiene.

The thermal conversion of cis-bicyclo[4.2.0]oct-7-ene to cis,cis-1,3-cyclooctadiene might involve a direct disrotatory ring opening, or it might possibly take place by way of cis,trans-1,3-cyclooctadiene.

Thermal disrotatory electrocyclic isomerization of cis-bicyclo[4.2.0]oct-7-ene to cis,cis-1,3-cyclooctadiene.

[reaction: see text] The ratio of observed rate constants, k/k', for thermal isomerizations of cis-bicyclo[4.2.0]oct-7-ene and its 2,2,5,5-d(4) analogue to cis,cis-1,3-cyclooctadienes at 250 degrees C is 1.

Thermal [1,3] carbon sigmatropic rearrangements of vinylcyclobutanes.

Stereochemical, kinetic, and theory-based studies of the [1,3] carbon sigmatropic rearrangements of bicyclo[2.1.1]hex-2-enes, bicyclo[3.