6705-46-0Relevant articles and documents
Oxyfunctionalization of non-natural targets by dioxiranes. 5. Selective oxidation of hydrocarbons bearing cyclopropyl moieties
D'Accolti, Lucia,Dinoi, Anna,Fusco, Caterina,Russo, Antonella,Curci, Ruggero
, p. 7806 - 7810 (2007/10/03)
The powerful methyl(trifluoromethyl)dioxirane (lb) was employed to achieve the direct oxyfunctionalization of 2,4-didehydroadamantane (5), spiro[cyclopropane-1,2′-adamantane] (9), spiro[2.5]-octane (17), and bicyclo[6.1.0]nonane (19). The results are compared with those attained in the analogous oxidation of two alkylcyclopropanes, i.e., n-butylcyclopropane (11) and (3-methyl-butyl)-cyclopropane (14). The product distributions observed for 11 and 14 show that cyclopropyl activation of α-C-H bonds largely prevails when no tertiary C-H are present in the open chain in the tether; however, in the oxyfunctionalixation of 14 cyclopropyl activation competes only mildly with hydroxylation at the tertiary C-H. The application of dioxirane 1b to polycyclic alkanes possessing a sufficiently rigid framework (such as 5 and 9) demonstrates the relevance of relative orientation of the cyclopropane moiety with respect to the proximal C-H undergoing oxidation. At one extreme, as observed in the oxidation of rigid spiro compound 9, even bridgehead tertiary C-H's become deactivated by the proximal cyclopropyl moiety laying in the unfavorable eclipsed (perpendicular) orientation; at the other end, a cyclopropane moiety constrained in a favorable bisected orientation (as for didehydroadamantane 5) can activate an α methylene CH2 to compete effectively with dioxirane O-insertion into tertiary C-H bonds. Comparison with literature reports describing similar oxidations by dimethyldioxirane (1a) demonstrate that methyl(trifluoromethyl)dioxirane (1b) presents similar selectivity and remarkably superior reactivity.
Regioselective Route to Sterically Hindered Cyclopropylcarbinyl Halides
Hrubiec, Robert T.,Smith, Michael B.
, p. 431 - 435 (2007/10/02)
Reaction of cyclopropylcarbinyl alcohols 1 with hexachloroacetone and triphenylphosphine resulted in 80 - 90 percent yields of the corresponding cyclopropylcarbinyl chlorides 4 regioselectively, with no trace of the homoallylic chloride 2 or the chlorocyclobutane derivative 6a.Similar reaction of 1 with bromine and triphenylphosphine, in dimethylformamide, gave 65 - 80 percent yields of the cyclopropylcarbinyl bromide 5 with trace amounts of the homoallylic bromide 3 but no detectable bromocyclobutane derivative 6b.These reactions are amenable to the preparation of very sterically hindered cyclopropylcarbonyl halides, heretofore inaccessible, regioselectively and in a facile manner.
Synthesis and Antimalarial Activity of 8--6-methoxy-4-methylquinolines
Yan, Shou-Jen,Chien, Ping-Lu,Cheng, C. C.
, p. 215 - 217 (2007/10/02)
Three analogues of the causal prophylactic antimalarial primaquine were prepared and their antimalarial activity was evaluated. 8--6-methoxy-4-methylquinoline (2a) demonstrated activity against Plasmodium berghei in mice at 20 mg/kg, with all animals cured at 320 mg/kg, and is without toxicity at 640 mg/kg.It also possessed outstanding causal prophylactic activity against Plasmodium cynomolgi in rhesus monkeys at very low dosages.
