34413-88-2Relevant articles and documents
Asymmetric Synthesis of Oxygenated Monoterpenoids of Importance for Bark Beetle Ecology
Ganji, Suresh,Svensson, Fredric G.,Unelius, C. Rikard
, p. 3332 - 3337 (2020/11/30)
Herein we report the asymmetric syntheses of a number of oxygenated terpenoids that are of importance in the chemical ecology of bark beetles. These are pinocamphones, isopinocamphones, pinocarvones, and 4-thujanols (= sabinene hydrates). The camphones were synthesized from isopinocampheol, the pinocarvones from β-pinene, and the thujanols from sabinene. The NMR spectroscopic data, specific rotations, and elution orders of their stereoisomers on a chiral GC-phase (β-cyclodextrin) are also reported. This enables facile synthesis of pure compounds for biological activity studies and identification of stereoisomers in mixed natural samples.
Peculiarities of β-pinene autoxidation
Neuenschwander, Ulrich,Meier, Emanuel,Hermans, Ive
experimental part, p. 1613 - 1621 (2012/03/11)
The thermal oxidation of the renewable olefin β-pinene with molecular oxygen was experimentally and computationally investigated. Peroxyl radicals abstract weakly bonded allylic hydrogen atoms from the substrate, yielding allylic hydroperoxides (i.e., myrtenyl and pinocarvyl hydroperoxide). In addition, peroxyl radicals add to the C=C bond of the substrate to form an epoxide. It was found that a relatively high peroxyl radical concentration, together with the high rate of peroxyl cross-reactions, make radical-radical reactions surprisingly important for this particular substrate. Approximately 60% of these peroxyl cross-reactions lead to termination (radical destruction), keeping a radical chain length of approximately 4 at 10% conversion. Numerical simulation of the reaction-based on the proposed reaction mechanism and known or predicted rate constants-demonstrate the importance of peroxyl cross-reactions for the formation of alkoxyl radicals, which are the precursor of alcohol and ketone products. Copyright
Hydroxylation by Cytochrome P-450 and Metalloporphyrin Models. Evidence for Allylic Rearrangement
Groves, John T.,Subramanian, Durga V.
, p. 2177 - 2181 (2007/10/02)
The allylic hydroxylation of 3,3,6,6-tetradeuteriocyclohexene, methylenecyclohexane, and β-pinene has been examined with phenobarbital-induced liver microsomal cytochrome P-450 (P-450LM2) and with iron porphyrin and chromium porphyrin model systems.Aerobic and peroxide dependent enzymic regimes were investigated with purified P-450LM2 and with microsomal suspensions.Epoxidation and allylic hydroxylation were primary reactions with all substrates.With 3,3,6,6-tetradeuteriocyclohexene, the major hydroxylation product (60-80percent) was the result of hydroxylation at the deuterated allylic site.In all cases, a significant amount (20-40percent) of hydroxylation occurred with allylic rearrangement.The iron porphyrin/iodosylbenzene model system also showed preferential hydroxylation of the deuterated allylic site (70percent) with significant allylic rearrangement (30percent).By contrast, the chromium porphyrin/iodosylbenzene model system showed complete scrambling of the allylic system.Extensive rearrangement accompanied the hydroxylation of methylenecyclohexane and β-pinene by both the enzymic and metalloporphyrin systems whereas the selenium dioxide oxidation of these substrates gave selective allylic hydroxylation without rearrangement.A mechanism is suggested for allylic hydroxylation by cytochrome P-450 and by the metalloporhyrin model systems involving initial hydrogen atom abstraction from the allylic site and geminate, cage recombination of the incipient, allylic free radical.
