Phencyclidine (I) and its derivatives show such pharmacological behaviors as analgesic, anticonsulvant, anti-anxiety and antidepressant, while interacting with central nervous system. In this study, new methyl and hydroxylderivatives of PCP were synthesized and their antinociceptive behaviors in animals were examined by measuring the number of writhing in a writhing test of visceral pain and the pain
Organocatalytic, Chemoselective, and Stereospecific House–Meinwald Rearrangement of Trisubstituted Epoxides
作者:Peter R. Schreiner、Friedemann Dressler、Victoria Öhler、Christopher Topp
DOI:10.1055/a-2216-4710
日期:——
We present a novel method for the chemoselective House–Meinwald rearrangement of trisubstituted epoxides under mild conditions with the use of simple perfluorinated disulfonimides as Brønsted acid catalysts. We isolated the α-quaternary aldehyde products in yields of 27–97% using catalyst loadings as low as 0.5 mol% on a scale of 1 mmol. In addition, we show the stereospecific rearrangement using an
Acid-Catalyzed Phenylcyclohexene Oxide Hydrolysis: Role of Para-Phenyl Substituent on Syn:Anti Hydration Ratio
作者:Lanxuan Doan、Kevin Bradley、Sonya Gerdes、Dale L. Whalen
DOI:10.1021/jo990220z
日期:1999.8.1
Rate and product studies of the hydronium ion-catalyzed hydrolysis of 1-phenylcyclohexene oxide and its p-methoxy and p-methyl derivatives in 1:9 dioxane-water solutions were carried out under conditions in which the diol products are stable. It is shown that the cis:trans diol ratio from hydrolysis of this series of epoxides does not systematically increase with the electron-donating ability of the para-substituent, contrary to conclusions in the literature. The equilibrium constants and rates for acid-catalyzed approach to equilibration of cis- and trans-1-(p-methoxyphenyl)cyclohexane-1,2-diol and of cis- and trans-1-(p-methylphenyl)cyclohexane-1,2-diol were measured, and the cis-diol was determined to be the more stable isomer in each case. An intermediate in the acid-catalyzed hydrolysis of 1-(p-methoxyphenyl)cyclohexene oxide is trapped, after its rate-limiting formation, by azide ion. For a series of 1-arylcyclohexene oxides, results are interpreted in terms of a mechanism in which there is a discrete carbocation intermediate, and products are determined solely by the partitioning reactions of this intermediate, with the pathway leading to the more stable product being energetically favored.