822-73-1Relevant academic research and scientific papers
Pyrolysis of Three Acetates of Methylbicycloheptan-2-ols and the Parent Alcohols
Vainiotalo, Pirjo,Pohjala, Esko,Maelkoenen, Pentti
, p. 1537 - 1540 (2007/10/02)
The acetates of exo-2-methyl-endo-bicycloheptan-2-ol, endo-2-methyl-exo-bicycloheptan-2-ol, and 1-methyl-exo-bicycloheptan-2-ol together the parent alcohols have been pyrolysed at several temperatures and the product distribution determined.The mechanism and direction of elimination in relation to structure are discussed qualitatively.The formation of the principal products is consistent with a concerted elimination involving a six-membered cyclic transition state.Wagner-Meerwein rearrangement occurs as a competing reaction in cases where the formation of a tertiary structure is possible at the expense of a secondary one.In the case studied a two-step reaction is considerably faster than direct pyrolysis of the secondary structure.
Stereochemistry of acid-catalyzed cleavage of 7-chloro-1-methylnortricyclene in deuterated medium; evidence for edge protonation of nortricyclenes
Werstiuk, Nick Henry,Cappelli, Frank Peter
, p. 1725 - 1737 (2007/10/02)
Cleavage of 7-chloro-1-methylnortricyclene (1e) in D2SO4-DOAc yields deuterated syn-7-chloro-1-methyl-exo-2-norbornyl acetate (3a-d) (1.04 excess d per molecule) and deuterated anti-7-chloro-1-methyl-exo-2-norbornyl acetate (3b-d) (1.28 excess d per molecule) as the kinetic products. 1H and 2H nuclear magnetic resonance spectroscopic analysis of the corresponding alcohols complexed with Eu(fod)3 shows the deuterium is located endo at C-6 and in the methyl group of the syn-7-chloroacetate, endo at C-6 and C-2, at C-7, and in the methyl group of the anti-7-chloroacetate.That the deuterium at C-6 of both acetates is 80-90percent stereochemically pure endo, in our view, establishes that the bond farthest removed from the electron-withdrawing chlorine is preferentially cleaved via edge deuteronation.
Ring-opening of Some Radicals containing the Cyclopropylmethyl System
Beckwith, Athelstan L. J.,Moad, Graeme
, p. 1473 - 1482 (2007/10/02)
Mono- and bi-cyclic radicals containing the cyclopropylmethyl system are readily generated by interaction of the appropriate halides with triphenyl- or tributyl-stannane.Each radical studied underwent ring-opening by fission of the more substituted βγ-bond.In the case of the secondary radical (12b) the new double bond was formed preferentially in the trans-configuration.Rate constants, which cannot be determined with high accuracy by this method, lie in the range 1E7-3E8 s-1 at 25 deg C.When generated by the flow method in the e.s.r. cavity α-hydroxycyclopropylmethyl radicals undergo β-fission followed by 1,5-hydrogen atom t ransfer to afford enoxyl radicals.The latter reaction occurs more slowly in water than in non-polar solvents.The rigid hydroxynortricyclyl (43) undergoes preferential fission of the less substituted βγ-bond, possibly because of the dipolar nature of the transition state.
