- Synthesis of the Enantiomeric K-Region Arene 5,6-Oxides Derived from Chrysene, 7,12-Dimethylbenzanthracene, and Benzophenanthrene
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K-region arene 5,6-oxides of chrysene, benzophenanthrene Ph>, and 7,12-dimethylbenzanthracene (DMBA) have been synthesized from resolved cis-5,6-dihydrodiols by the ortho ester route as well as from separated bromo(menthyloxy)acetate precursors in the cases of chrysene and BPh.Absolute configurations of the 5,6-oxides and their precursors from chrysene and DMBA have been determined by nucleophilic trans addition of methanol to the oxirane ring and correlation by circular dichroism of the adducts with trans dihydrodiols of known configurations.Confirmation of the configurational assigments to the enantiomeric chrysene cis-5,6-dihydrodiols was achieved by reduction to cis-5,6-dihydroxy-1,2,3,4,5,6-hexahydrochrysene and determination of the skew sense of the resulting biphenyl chromophore through CD measurements.BPh 5,6-oxide enantiomers were assigned by direct comparision with a sample of known configuration on a chiral column.
- Balani, Suresh K.,Bladeren, Peter J. van,Cassidy, E. Sally,Boyd, Derek R.,Jerina, Donald M.
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p. 137 - 144
(2007/10/02)
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- Resolution and Absolute Configuration of K-Region Trans Dihydrodiols from Polycyclic Aromatic Hydrocarbons
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K-region trans dihydrodiols of benzophenanthrene, chrysene, pyrene, and dibenzacridine have been resolved as their diastereomeric diesters with (-)-(menthyloxy)acetic acid, and their absolute configuration have been assigned by the application of circular dichroism and excition chirality methods.For these as well as the K-region trans dihydrodiol derivatives from five other hydrocarbons, a consistent pattern of physical properties has emerged.The R,R diastereomers are less retained on silica gel HPLC columns when eluted with ether-cyclohexane mixtures and show negative values of D in tetrahydrofuran, the degree of magnetic nonequivalence between HA and HB in the -OCHAHBCO2- portion of the diesters (100 MHz, C6D6) is generally much higher for the S,S enantiomers of the dihydrodiols, and the free R,R dihydrodiols have positive values of D in tetrahydrofuran provided their hydroxyl groups do not have a marked preference for the pseudodiaxial conformation.
- Balani, S. K.,Bladeren, P. J. van,Shirai, N.,Jerina, D. M.
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p. 1773 - 1778
(2007/10/02)
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