Thermal bridgehead double inversion of the 6-methylene- and 6-ethylidene-2-methylbicyclo[3.1.0]hexanes. Rotational kinetic deuterium isotope effects and the mechanism of the thermal interconversion of cis- and trans-2,3-dimethylmethylenecyclopropanes via trimethylenemethane singlet biradicals
Thermal bridgehead double inversion of the 6-methylene- and 6-ethylidene-2-methylbicyclo[3.1.0]hexanes. Rotational kinetic deuterium isotope effects and the mechanism of the thermal interconversion of cis- and trans-2,3-dimethylmethylenecyclopropanes via trimethylenemethane singlet biradicals
作者:Joseph J. Gajewski、Charles W. Benner、Bruce N. Stahlly、Ralph F. Hall、Ronald I. Sato
DOI:10.1016/0040-4020(82)80166-x
日期:1982.1
cis- and trans - 2,3 - Dimethylenemethylenecyclopropane (C and T) interconvert at 160.0° with a small normal kinetic isotope effect (KIE) when the exo-methylene is deuterated, but the 1,3-shift products, 2-methylethylidenecyclopropane, show a large normal KIE, 1.35 and 1.31, when formed from C and T, respectively. This data can be interpreted in terms of either parallel reactions or a common trimethylenemethane
Ring cleavage rearrangement of methyl-subsituted cyclopropylmethylboranes
作者:E. Alexander Hill、Young-Whan Park
DOI:10.1016/0022-328x(88)80667-3
日期:1988.11
30dimethylmethylenecyclopropane were prepared and hydroborated using various borane reagents. Changes in the borane solutions as a result of heating were studied by NMR and by oxidation to alcoholds. Ring-cleavage rearrangement reactions were observed, analogous to rearrangements previously found for cyclopropylmethyl Grignardreagents and for unsubstituted cyclopropylmethylboranes Methyl substitution slows the
Synthesis and mechanism of formation of dicarbonyl(η<sup>4</sup>-trimethylenemethane)(η<sup>5</sup>-pentamethylcyclopentadienyl)molybdenum tetrafluoroborate
作者:Stephen G. Barnes、Michael Green
DOI:10.1039/c39800000267
日期:——
Reaction of [Mo(CO)3(η5-C5Me5)]BF4 generated from [Mo(CO)3(η5-C5Me5)]2 and AgBF4 with methylenecyclopropane, cis-, and trans-2,3-dimethylmethylenecyclopropanes affords dicarbonyl(η4-trimethylenemethane)(η5-pentamethylcyclopentadienyl)molybdenum tetrafluoroborate complexes, the stereochemistry of the reactions implicating a disrotatory ring-opening reaction.