40213-64-7Relevant articles and documents
Parallel and competitive pathways for substrate desaturation, hydroxylation, and radical rearrangement by the non-heme diiron hydroxylase AlkB
Cooper, Harriet L. R.,Mishra, Girish,Huang, Xiongyi,Pender-Cudlip, Marilla,Austin, Rachel N.,Shanklin, John,Groves, John T.
, p. 20365 - 20375 (2013/02/25)
A purified and highly active form of the non-heme diiron hydroxylase AlkB was investigated using the diagnostic probe substrate norcarane. The reaction afforded C2 (26%) and C3 (43%) hydroxylation and desaturation products (31%). Initial C-H cleavage at C2 led to 7% C2 hydroxylation and 19% 3-hydroxymethylcyclohexene, a rearrangement product characteristic of a radical rearrangement pathway. A deuterated substrate analogue, 3,3,4,4-norcarane-d 4, afforded drastically reduced amounts of C3 alcohol (8%) and desaturation products (5%), while the radical rearranged alcohol was now the major product (65%). This change in product ratios indicates a large kinetic hydrogen isotope effect of ～20 for both the C-H hydroxylation at C3 and the desaturation pathway, with all of the desaturation originating via hydrogen abstraction at C3 and not C2. The data indicate that AlkB reacts with norcarane via initial C-H hydrogen abstraction from C2 or C3 and that the three pathways, C3 hydroxylation, C3 desaturation, and C2 hydroxylation/radical rearrangement, are parallel and competitive. Thus, the incipient radical at C3 either reacts with the iron-oxo center to form an alcohol or proceeds along the desaturation pathway via a second H-abstraction to afford both 2-norcarene and 3-norcarene. Subsequent reactions of these norcarenes lead to detectable amounts of hydroxylation products and toluene. By contrast, the 2-norcaranyl radical intermediate leads to C2 hydroxylation and the diagnostic radical rearrangement, but this radical apparently does not afford desaturation products. The results indicate that C-H hydroxylation and desaturation follow analogous stepwise reaction channels via carbon radicals that diverge at the product-forming step.
Molecules with Twist Bent Bonds. The Synthesis, Properties, and Reactions of trans-Bicyclohept-3-ene and Certain Methylated Derivatives
Gassman, Paul G.,Bonser, Steven M.,Mlinaric-Majerski, Kata
, p. 2652 - 2662 (2007/10/02)
trans-Bicyclohept-3-ene, 7-methyl-trans-bicyclohept-3-ene, and 7,7-dimethyl-trans-bicyclohept-3-ene have been synthesized.Comparison of their ease of oxidation with the ease of oxidation of the analogous cis-bicyclohept-3-enes has been made.Both the thermal and transition-metal complex promoted rearrangements of the trans-bicyclohept-3-enes have been studied.These systems thermally convert to the cis-bicyclohept-3-enes above 100 deg C and are catalytically rearranged at ambient temperature.Trans to cis isomerization alsooccurs at ambient temperature under photoinduced single electron transfer conditions.
Synthesis of Polycyclic Homocyclopropylcarbinols by Reductive Cyclization of Bromocyclopropyl Epoxides
Last, Larry A.,Fretz, E. Robert,Coates, Robert M.
, p. 3211 - 3219 (2007/10/02)
A new synthetic route to polycyclic homocyclopropylcarbinols has been realized by lithiation of bromocyclopropyl epoxides with n-butyllithium and subsequent intramolecular attack of the metalated cyclopropane ring onto the epoxide.A series of seven bromoc
