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• 作者：Wadih Ghattas ; Corinna R. Hess ; Gilles Iacazio ; Renaud Hardré ; Judith P. Klinman ; Marius Ré ; glier
• 刊名：Journal of Organic Chemistry
• 出版年：2006
• 出版时间：October 27, 2006
• 年：2006
• 卷：71
• 期：22
• 页码：8618 - 8621
• 全文大小：88K
• 年卷期：v.71,no.22(October 27, 2006)
• ISSN：1520-6904

文摘

An efficient preparation of pure ethyl Z- and E-,-difluoro-4-phenyl-3-butenoate 1a and 1b together with the corresponding acids 2a and 2b is described. The proceduresinvolve stereocontrolled additions of CF₂CO₂Et to phenylacetylene or -bromostyrene. Compound 1a is easily obtained by addition of CF₂CO₂Et to phenylacetylene via amechanism where the stereochemistry is controlled by anelectron-transfer process to produce predominantly the Zvinyl anion. The product 1b is obtained by CF₂CO₂Etaddition-elimination to Z- or E--bromostyrenes via amechanism where the stereochemistry is controlled by stericfactors in the conformational equilibration of the intermediates.