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The α-hydroxyphosphonate-phosphate rearrangement of a noncyclic substrate - some new observations.

Research paper by Susanne S Prechelmacher, Kurt K Mereiter, Friedrich F Hammerschmidt

Indexed on: 03 May '18Published on: 03 May '18Published in: Organic & Biomolecular Chemistry



Abstract

Racemic ethyl hydrogen (1-hydroxy-2-methylsulfanyl-1-phenylethyl)phosphonate was resolved with (R)-1-phenylethylamine. The (R)-configuration of the (-)-enantiomer was determined by chemical correlation. Esterification of the (-)-enantiomer with a substituted diazomethane derived from 3-hydroxy-1,3,5(10)-estratrien-17-one delivered two epimeric phosphonates separated by HPLC. Methylation with methyl fluorosulfate at the sulfur atom and treatment with a strong base induced an α-hydroxyphosphonate-phosphate rearrangement with formation of dimethyl sulphide and two enantiomerically pure enol phosphates. Their oily nature interfered with a single crystal X-ray structure analysis to determine the stereochemistry at the phosphorus atom.