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The wittig reaction of non-stabilized phosphorus ylides and aromatic aldehydes. Studies on erythro and threo β-hydroxyphosphonium salts and the promotion of stereochemical drift by synergism between diastereomers

✍ Scribed by Bruce E. Maryanoff; Allen B. Reitz


Publisher
Elsevier Science
Year
1985
Tongue
French
Weight
293 KB
Volume
26
Category
Article
ISSN
0040-4039

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✦ Synopsis


In deprotonation studies with isomerically pure ervthro-3 and m-3, "retro-Wittig" reaction was only detected for erythro-3. Mixtures of erythro-3 and threo-3. under -_ lithium salt-free conditions, undergo stereochemical drift because of synergism between diastereomeric oxaphosphetanes cis-2 and trans-2 during their decomposition to alkenes. -_ --Recently, we have observed' individual cis and trans oxaphosphetanes in the Wittig reaction of non-stabilized phosphorus ylides and aldehydes by 145.8~MHz 31P and 90.5MHz 13C NHR.2