39834-44-1Relevant academic research and scientific papers
A General Method for the Resolution of Cyclic trans-Bromohydrin Enantiomers. Absolute Configuration by Crystal Structure Analysis of a 2-Methoxy-2-phenyl-2-trifluoromethylacetate (MTPA) Diastereoisomer
Balani, Suresh K.,Boyd, Derek R.,Cassidy, E. Sally,Devine, Gregory I.,Malone, John F.,et al.
, p. 2751 - 2756 (2007/10/02)
trans-Bromohydrins of 1,2,3,4-tetrahydronaphthalene (1a), 1,2,3,4-tetrahydroanthracene (1b), and 1,2,3,4-tetrahydrophenanthrene (1c) and (1d) were isolated in optically pure forms by reductive cleavage of the corresponding 2-methoxy-2-phenyl-2-trifluoromethylacetate (MTPA) diastereoisomers (2a-d) which had been separated by preparative h.p.l.c.Using reactions with established mechanisms and stereochemistry, the configurations at the chiral centres in the bromohydrins (1) were correlated with those in the tetrahydroepoxides (5), the arene oxides (7), and cis- (3) and trans- (4) tetrahydrodiols.An X-ray structure analysis of the 1,2,3,4-tetrahydroanthracene bromo-MTPA ester (+)-(2bE) indicated the trans equatorial quasi-equatorial conformation and confirmed the absolute stereochemistry of the MTPA group as (S).
AN IMPROVED METHOD FOR THE SYNTHESIS OF OPTICALLY PURE EPOXIDE AND ALCOHOL DERIVATIVES OF CHIRAL BROMOHYDRINS
Balani, Suresh K.,Boyd, Derek R.,Cassidy, E. Sally,Greene, Ruth M. E.,McCombe, Kenneth M.,et. al.
, p. 3277 - 3280 (2007/10/02)
The resolution of arene oxides, diols and other derivatives of bromohydrins has been markedly improved by the use of bromohydrin esters of (-)-(S)-α-methoxy-α-trifluoromethyl-phenylacetic acid (MTPA).
Stereochemical and Mechanistic Aspects of Sulphoxide, Epoxide, Arene Oxide, and Phenol Formation by Photochemical Oxygen Atom Transfer from Aza-aromatic N-Oxides
Akhtar, M. Naseem,Boyd, Derek R.,Neill, John D.,Jerina, Donald M.
, p. 1693 - 1699 (2007/10/02)
Stereoselectivity and relative yields are determined for the sulphoxide formation resulting from the u.v. irradiation of a range of aza-aromatic N-oxides in the presence of cyclic thioethers.A comparison is made with the results of oxidation by oxaziridines and by mono-oxygenase enzymes present in the fungus Aspergillus niger.The photochemical oxidation results are consistent with a transition state involving an oxaziridine intermediate where partial bonding of the oxygen atom to the ring nitrogen atom is maintained during the oxygen transfer process.Photolysis of aza-aromatic N-oxides in the presence of cis- and trans-olefins yields epoxides. cis-4-Methylpent-2-ene yielded both cis and trans-epoxides in almost equal proportions indicating that the oxygen atom addition to a carbon-carbon bond in this system is non-concerted.The photochemically induced oxygenation of perdeuteriated aromatic substrates provides no evidence for direct insertion of an oxygen atom into an aromatic carbon-hydrogen bond.Addition of an oxygen atom to form an epoxide (arene oxide) intermediate in this system is evidenced by the NIH shift in a wide range of aromatic substrates, and by the detection of arene oxide intermediates (and their isomeric phenols) from naphthalene and phenanthrene.
