Premium
Synthesis of Enantiomerically Pure 1,5,5‐Trideuterated cis‐ and trans ‐2,4‐Dioxa‐3‐phosphadecalins. 31 P‐NMR Evidence of Covalent‐Bond Formation and the Stereochemical Implications in the Course of the Inhibition of δ ‐Chymotrypsin
Author(s) -
Stöckli Markus J.,
Rüedi Peter
Publication year - 2007
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200790215
Subject(s) - chemistry , walden inversion , stereochemistry , covalent bond , vicinal , moiety , decane , nuclear magnetic resonance spectroscopy , proton nmr , crystallography , organic chemistry
The irreversible inhibition of δ ‐chymotrypsin with the enantiomerically pure, P(3)‐axially and P(3)‐equatorially X‐substituted cis‐ and trans‐ configurated 2,4‐dioxa‐3‐phospha(1,5,5‐ 2 H 3 )bicyclo[4.4.0]decane 3‐oxides (X=F, 2,4‐dinitrophenoxy) was monitored by 31 P‐NMR spectroscopy. 1 H‐Correlated 31 P{ 2 H}‐NMR spectra enabled the direct observation of the vicinal coupling ( 3 J ) between the P‐atom of the inhibitor and the CH 2 O moiety of Ser 195 (=‘Ser 195 ’(C H 2 O)), thus establishing the covalent nature of the ‘Ser 195 ’(CH 2 OP) bond in the inhibited enzyme. The stereochemical course of the phosphorylation is dependent on the structure of the inhibitor, and neat inversion, both inversion and retention, as well as neat retention of the configuration at the P‐atom was found.