16631-66-6Relevant academic research and scientific papers
Molecules with Twist Bent Bonds. A Comparison of the Thermal and Transition-Metal-Complex Promoted Rearrangements of Derivatives of trans-Bicyclohept-3-ene
Gassman, Paul G.,Mlinaric-Majerski, Kata
, p. 4803 - 4806 (1988)
7-Methyl-trans-bicyclohept-3-ene has been synthesized and the thermal and transition-metal-complex promoted rearrangements of trans-bicyclohept-3-ene, 7-methyl-trans-bicyclohept-3-ene, and 7,7-dimethyl-trans-bicyclohept-3-ene have been compared.
Organocatalytic multicomponent α-methylenation/diels-alder reactions: A versatile route to substituted cyclohexenecarbaldehyde derivatives
Zou, Yue,Wang, Quanrui,Goeke, Andreas
scheme or table, p. 5335 - 5345 (2009/05/28)
This article describes the design and optimization of an effective organocatalytic three-componentdomino α-methylenation/Diels-Alder reaction to produce vinyl-substituted cyclohexenecarboxaldehydes in a highly regioselective fashion. In these one-pot transformations, 2-formyl-1,3- butadienes (4) were prepared in situ from α,β-unsaturated aldehydes and formalin and were subsequently trapped with a variety of buta-l,3-dienes. The outcomes of the reactions were dependent on the electronic properties of the dienes. 1-Vinylcyclohexenecarbaldehydes 6 were formed by use of acyclic electron-rich dienes, while the initially formed cycloadducts of 4 with cyclopentadiene underwent Cope rearrangements, leading to the formation of tetrahydro-3H-indene-5-carbaldehyde compounds 7. The mechanisms involved in these reactions were deduced from experimental findings. Furthermore, the method was also extended to one-pot domino methylenation/ Diels-Alder reactions of dihydrofurans and dihydropyrans to yield spirocyclic lactols 22. In these reactions, the unstable intermediate hydroxyethyl and hydroxypropyl acroleins behaved as dienophiles, undergoing cycloaddition reactions with dienes with good yields and selectivities. The wide variety of functionalized 1-vinylcyclohex-3-enecarbaldehydes 6, 4-vinylcyclohex-l-enecarbaldehydes 7, and spiro lactols 22 generated through the use of these organocatalytic domino processes as a diversityoriented synthesis provided useful intermediates for the construction of novel odorants.
Organic Photochemistry with 6.7-eV Photons. The Divergent Photobehavior of exo- and endo-7-Methyl-2-norcarene
Leigh, William J.,Srinivasan, R.
, p. 3970 - 3979 (2007/10/02)
The photochemistry of exo- and endo-7-methylbicyclohept-2-ene (7-methyl-2-norcarene) upon direct and toluene-sensitized photolysis has been investigated.Direct photolysis of the two isomers in hydrocarbon solution with monochromatic 214-nm light leads to widely divergent photobehavior.Ring opening, yielding cis-5-methyl-1,3,6-heptatriene (via a formal process), and exo-endo isomerization are major decomposition pathways in both cases, accounting for 30-45percent of the observed products.The formation of 7-methylnorbornene and 4-methylbicyclohept-2-ene is observed to proceed stereospecifically in each case, while the formation of cyclopropyl ring opening/hydrogen migration products appears to depend strongly on the orientation of the methyl group in the starting isomer.Common biradical intermediates are thus believed not to be involved in the direct photolyses of 2 and 3.Toluene-sensitized photolysis of the two isomers leads to formation of exo-4-methylbicyclohept-2-ene (the photochemical vinylcyclopropane rearrangement) and exo-endo isomerization.These results are rationalized in terms of the expected behavior of two common biradical intermediates, which are formed with different efficiencies from the isomeric 2 and 3 upon triplet sensitization.
