Double Diastereoselection in Aldol Reactions Mediated by Dicyclohexylchloroborane between l -Erythrulose Derivatives and Chiral Aldehydes. The Felkin−Anh versus Cornforth Dichotomy
2003; American Chemical Society; Volume: 68; Issue: 22 Linguagem: Inglês
10.1021/jo035159j
ISSN1520-6904
AutoresJ. Alberto Marco, Miguel Cardá, Santiago Díaz‐Oltra, Juan Murga, Eva Falomir, H. Roeper,
Tópico(s)Fluorine in Organic Chemistry
ResumoBoth matched and mismatched diastereoselections have been observed in aldol reactions of the B,B-dicyclohexylboron enolate of a protected l-erythrulose derivative with a range of chiral aldehydes. The stereochemical outcome of reactions with alpha-methyl aldehydes can be adequately explained within the Felkin-Anh paradigm. In the case of alpha-oxygenated aldehydes, however, strict adherence to this model does not allow for a satisfactory account of the observed results. In such cases, the Cornforth model provides a much better explanation.
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