- Enantiomerically pure cyclic trans-1,2-diols, diamines, and amino alcohols by intramolecular pinacol coupling of planar chiral mono-Cr(CO)3 complexes of biaryls
-
Without any formation of stereoisomers, the intramolecular pinacol cyclization of 1 - planar chiral mono-Cr(CO)3 complexes of 1,1'-biphenyls with carbonyl functionalities at the 2- and 2'-positions - with samarium diiodide gives cyclic trans-1,
- Taniguchi,Taniguchi, Nobukazu,Hata,Hata, Takeshi,Uemura,Uemura, Motokazu
-
p. 1232 - 1235
(2007/10/03)
-
- Resolution and Absolute Configuration of K-Region Trans Dihydrodiols from Polycyclic Aromatic Hydrocarbons
-
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.
-
p. 1773 - 1778
(2007/10/02)
-