66165-06-8Relevant articles and documents
Pathways and Stereochemistry of Rearrangements in Reactions of Sulfenyl Chlorides with Alkenes
Borisov, A. V.,Bodrikov, I. V.,Borisova, G. N.,Smit, V. A.,Lutsenko, A. I.,Bel'skii, V. K.
, p. 943 - 951 (2007/10/03)
In reactions of 3,3-dimethyl-1-butene and 3-methyl-1-butene with 2,4-dinitrobenzenesulfenyl chloride in the systems M(ClO4)n-CH3NO2 (M=Li or Mg), 1,2 shifts of the methyl group and hydride ion respectively occur directly within the AdE process (? pathway of the rearrangement).In the same systems reactions of these alkenes with arenesulfenyl chlorides containing in the electrophilic moiety less electronegative substituents, as compared to the dinitrophenyl group, initially yield β-chloro sulfides, which under reaction conditions mostly undergo rearrangements (? pathway of the rearrangement).In nitromethane in the presence of LiClO4, AlCl3, or AgBF4 erythro-2-arylthio-1-chloro-1-deutero-2,3-dimethylbutanes are converted into stereoisomeric thiochromans; their ratio is controlled by the nature of the metal compound added, electronic properties of substituents in the arylthio moiety, and reaction temperature.
Conformationally Restricted Retinoids
Dawson, Marcia I.,Hobbs, Peter D.,Derdzinski, Krzysztof,Chan, Rebecca L.-S.,Gruber, John,et al.
, p. 1516 - 1531 (2007/10/02)
A series of conformationally restricted retinoids was synthesized and screened in two assays used to measure the ability of retinoids to control cell differentiation, namely, the reversal of keratinization in tracheal organ culture from vitamin A deficient hamsters and the inhibition of the induction of mouse epidermal ornithine decarboxylase by a tumor promoter.These compounds had bonds corresponding to selected bonds of the E-tetraene chain of retinoic acid (1) held in a planar cisoid conformation by inclusion in an aromatic ring.The meta-substituted analogue 3 of 4-benzoic acid (2) was far less active than 2 in both assays.In contrast, the vinyl homologue of 2 (4) and the 7,8-dihydro and 7,8-methano analogues (5 and 6) had activity comparable to that of 2.Analogues of 4-benzoic acid (7) were also screened.Replacement of the tetrahydronaphthalene ring of 7 by a benzonorbornenyl group (9) significantly reduced activity, as did removal of the vinylic methyl group from 9 (10).Replacement of the propenyl group of 9 by a cyclopropane ring (12) also reduced activity.Replacement of the tetrahydronaphthalene ring of 7 by 4,4-dimethyl-3,4-dihydro-2H-1-benzopyran and -benzothiopyran rings (13 and 14) also decreased activity.Inclusion of the 7,9 double bond system of 1 in an aromatic ring (15 and 16) reduced activity, whereas inclusion of the 5,7 double bond system in an aromatic ring enhanced activity (7 and 19).Inclusion of the 11,13 and 9,11,13 double bond systems in aromatic rings (2 and 18) also reduced activity below that of 1.Retinoic acid, 7, 13, 14, and 19 inhibited papilloma tumor formation in mice.Toxicity testing indicated that 7 was more toxic than 1, 13, 14, and 19, 19 was more toxic than 1, and 13 and 14 were less toxic than 1.
