Deuterium chloride and deuterium alcohols from silane derivatives

Abstract

Methods are described here for the preparation of DCl and alcohols-OD from the corresponding silanes by simple and rapid procedures using heavy water.

Mechanism of aminolysis of .delta.-lactones. Kinetic behavior of tri-O-methyl-2-deoxyglucono-.delta.-lactone, solvent deuterium isotope effects, and transition-state characterization

“…4 On the other hand, the aminolysis reactions of phenyl acetates and other esters with Journal of the American Chemical Society / 98:20 / September moderately good leaving groups,15 i.e., with pvalues of leaving alcohol ranging from ca. 7 (/?-nitrophenol) to about 12.5 (trifluoroethanol), were shown to proceed without a change in rate-determining step over the entire pH range studied. 16 In the proposed mechanism6 the formation of the zwitterionic aminolysis intermediate T* is rapid and reversible for both the alkyl and moderately reactive phenyl acetates and by inference for the aminolysis of the present lactone (Scheme I).…”

Synthesis of specifically deuterated S-benzylcysteines and of oxytocin and related diastereomers deuterated in the half-cystine positions

“…A semiautomated apparatus designed and built in our laboratory was used which allowed the reaction vessel to be filled and emptied by application of vacuum at the top and bottom, respectively, of the vessel, and to be shaken mechanically. For each step, 35 ml of solvent was used except for the DIEA neutralization step in which case 40 ml was used. For this synthesis 0.8 equiv of DCC was used for each equivalent of Boc-amino acid.…”

“…35 We have obtained ethanol-d in 99.9% yield after only 2 h reaction time which was pure as judged by NMR and gas chromatography. These experiments required a rapid and inexpensive source of ethanol-d.…”

“…0.3%) of thionyl chloride which produced a slight concentration of D+ in solution. 35 We have obtained ethanol-d in 99.9% yield after only 2 h reaction time which was pure as judged by NMR and gas chromatography. S-Benzyl-DL-[/3,/3-2H2] cysteine (7) was readily resolved into its enantiomers by N-acetylation followed by reaction with hog renal acylase.36 A similar treatment of 6 and 8 separated the enantiomers without loss of label at either the a or ß positions.…”