A new mechanistic proposal for the origin of α-homoallylic alcohols in indium-mediated allylation reactions in water

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• 作者：Loh ; Teck-Peng ; Tan ; Kui-Thong ; Hu ; Qi-Ying
• 刊名：Tetrahedron Letters
• 出版年：2001
• 出版时间：December 3, 2001
• 年：2001
• 卷：42
• 期：49
• 页码：8705-8708
• 全文大小：136 K

文摘

A new mechanism is proposed for the α-regioselective indium-mediated allylation reaction in water. Based on the results and observations obtained from an NMR study, a cross-over experiment and the complete inversion of the stereochemistry of 22β γ-adduct homoallylic sterols to the 22α α-adduct homoallylic sterols, it is suggested that the initially formed γ-adduct undergoes a bond cleavage to generate the parent aldehyde in situ followed by a concerted rearrangement, perhaps a retro-ene reaction followed by a 2-oxonia [3,3]-sigmatropic rearrangement to furnish the α-adduct.