A study on the stereoselectivity of C,O bond formation in esterification of cyclic thiohydroxamic acids

作者：Hartung Jens^*; Kempter Irina; Gottwald Thomas; Schwarz Michaela; Kneuer Rainer

来源：Tetrahedron: Asymmetry , 2009, 20(18): 2097-2104.

DOI：10.1016/j.tetasy.2009.08.020

Esterification of cyclic thiohydroxamic acids, for example, N-hydroxypyridine-2(1H)-thione, N-hydroxy-4-metlylthiazole-2(3H)-thione, and N-hydroxy-4-(p-chloiophenyl)-thiazole-2(3H)-thione, occuried with inversion of configuration at the attacked stereocenter, as evident from the use of chiral alcohols, alkyl p-toluene sulfonates, and cyclic sulfates. Stereochemical analysis of enant omerically pure O-alkyl thiohydroxamates was performed on the basis of CD-spectroscopy and chemical derivatizition. The assignment of the relative configuration in cyclic O-esters was feasible via NMR spectroscopy, whereas chiral aliphatic glycolato monoesters required hydroxyl group derivatization with chloro-(4R,5R)bis[(1R,2S,5R)-menth-1-yloxycarbonyl)]-1,3,2-dioxaphospholane for this purpose.

• 出版日期2009-9-23