77123-27-4Relevant academic research and scientific papers
Synthesis of (-)-Conduramine A1, (-)-Conduramine A2 and (-)-Conduramine E2 in Six Steps from Cyclohexa-1,4-diene
Da Silva Pinto, Solange,Davies, Stephen G.,Fletcher, Ai M.,Roberts, Paul M.,Thomson, James E.
, p. 7933 - 7937 (2019)
A method to enable the synthesis of conduramines and their N-substituted derivatives (enantiopure or racemic form) in six steps (five steps for N-substituted derivatives) from cyclohexa-1,4-diene is reported. Key features of this reaction sequence include a preparation of benzene oxide that is amenable to multigram scale, and its efficient ring-opening upon treatment with a primary amine. Epoxidation of the resultant amino alcohols (40% aq HBF4 then m-CPBA) is accompanied by hydrolytic ring-opening in situ to give the corresponding N-substituted conduramine derivatives directly. These may undergo subsequent N-deprotection to give the parent conduramines, as demonstrated by the preparation of enantiopure (-)-conduramine A1, (-)-conduramine A2, and (-)-conduramine E2 (the latter two for the first time). The selectivity of the epoxidation reaction is proposed to be the result of competitive ammonium-directed and hydroxyl-directed epoxidation processes, followed by either direct (SN2-type) or conjugate (SN2′-type) ring-openings of the intermediate epoxides.
Base-Mediated Fragmentation of Bicyclic Dihydro-3,6-oxazines: Transformation of Nitroso Diels-Alder Cycloadducts
Campagne, Rémy,Sch?kel, Friederike,Guillot, Régis,Alezra, Valérie,Kouklovsky, Cyrille
, p. 1884 - 1887 (2018/04/16)
Nitroso Diels-Alder cycloadditions of benzene oxide with various acyl-nitroso derivatives are described. Treatment of these cycloadducts with methyllithium results in a fast fragmentation reaction, leading to highly functionalized cyclic amino alcohols. T
Stereoselective syntheses of racemic quercitols and bromoquercitols starting from cyclohexa-1,4-diene: Gala-, epi-, muco-, and neo-quercitol
Aydin, G?kay,Savran, Tahir,Akta?, Fatih,Baran, Arif,Balci, Metin
, p. 1511 - 1524 (2013/05/21)
The efficient synthesis of gala-, epi-, neo-, and muco-quercitols and some brominated quercitols starting from cyclohexa-1,4-diene is reported. Treatment of the dibromide, obtained by the addition of bromine to cyclohexa-1,4-diene, with m-chloroperbenzoic
?-Facial stereoselectivity in the Diels-Alder reactions of benzene oxides
Gillard, James R.,Newlands, Michael J.,Bridson, John N.,Burnell, D. Jean
, p. 1337 - 1343 (2007/10/02)
The Diels-Alder reactions of N-phenylmaleimide and dimethyl acetylenedicarboxylate with benzene oxide (1,3,5-cyclohexatriene 1,2-oxide, 3) and its more substituted derivatives 1,2-dimethyl-1,3,5-cyclohexatriene 1,2-oxide (7) and 10-oxatricyclodeca-2,4-diene (11) in a kinetic manner gave exclusively products of addition anti to the plane-nonsymmetrical oxygen.The structures of the adducts were determined unequivocally by nuclear Overhauser enhancements in their 1H nuclear magnetic resonance spectra and by X-ray crystallographic methods.The ?-facial stereoselectivity was rationalized in terms of unfavorable orbital interactions, steric hindrance between the dienophile and the syn face of benzene oxide, and ?-donation by the oxygen. Key words: cycloaddition, Diels-Alder, syn-anti, ?-facial stereoselectivity, benzene oxide.
