Comparing and taming the reactivity of HWE and Wittig reagents with cyclic hemiacetals
作者:Jokin Carrillo、Anna M. Costa、Mireia Sidera、Jaume Vilarrasa
DOI:10.1016/j.tetlet.2011.07.121
日期:2011.10
lactol) with conjugated phosphoranes (stabilisedWittig reagents) and Horner–Wadsworth–Emmons reagents is disclosed. The HWE reaction has a strong bias to give oxolanes. On the other hand, stabilisedWittig reagents give unsaturated carboxyl derivatives of configuration E (major) and oxolanes (minor); the latter can be avoided by addition of CF3CH2OH or using morpholine amide phosphorane.