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Utilisation d'ylides du phosphore en chimie des sucres XXIII Eliminations accompagnant certaines réactions de Wittig
Author(s) -
Tronchet Jean M. J.,
Cottet Christian,
BarbalatRey Françoise
Publication year - 1975
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.19750580531
Subject(s) - chemistry , wittig reaction , reagent , alkyl , stereochemistry , medicinal chemistry , nuclear magnetic resonance spectroscopy , ketone , organic chemistry
Some reactions of 3‐O‐alkyl‐6‐deoxy‐1,2‐O‐isopropylidene‐α‐D‐xylo‐hexofuranos‐5‐uloses (1 and 2) with Wittig reagents are described. These ketosugars react with methylenetriphenylphosphorane and benzylidenetriphenylphosphorane to give the expected unsaturated branched‐chain sugars and dienes formed by elimination of H–C(4) and the 3‐alkyloxy group. Structural studies on all these compounds have been effected using NMR. spectroscopy and particularly, when necessary, nuclear Overhauser Effect. One important by‐product of these reactions is an unsaturated ketone 3,6‐dideoxy‐1,2‐O‐isopropylidene‐α‐D‐ glycero ‐hex‐3‐enofuranos‐5‐ulose (6). Compounds 1 and 2 do not react with cyanomethylenetriphenylphosphorane.