Effect of buffer general acid-base catalysis on the stereoselectivity of ester and thioester H/D exchange in D2O.

As part of a comprehensive investigation on the stereochemistry of base-catalyzed 1,2-elimination and H/D exchange reactions of carbonyl compounds, we have found that the stereoselectivity of H/D exchange of 3-hydroxybutyryl N-acetylcysteamine (3) in D(2)O is strongly influenced by the presence of buffers. This buffer effect is also operative with a simple acyclic ester, ethyl 3-methoxybutanoate (7). Buffers whose general-acid components are cyclic tertiary ammonium ions are particularly effective in changing the stereoselectivity.

Characteristics of alcoholics and codependents who did and did not complete treatment.

Demographic data were collected on 803 patients who were treated for dependency/codependency issues at the Center for Problem Resolution (CPR) from September 1, 1986, until December 31, 1987. Comparisons were made between patients who completed treatment and noncompleters. Results are reported on the entire sample and then broken down into three patient categories.