Generation of acyl anion equivalents by in situ cathodic reduction of acyl tributylphosphonium ions anodically generated from tributylphosphine and carboxylic acids: preparation of α-hydroxy cycloalkanones from keto acids
The preparation of α-hydroxy cycloalkanones from keto acids was effectively achieved by constant current electrolysis in the presence of Bu3P in an undivided cell under an N2 atmosphere, where the α-oxy ylides generated by the in situ cathodic reduction of acyl tributylphosphonium ions, formed anodically from tributylphosphine and carboxylic acids, seems to function as a novel acyl anion equivalent.
Facile and Stereoselective Access to Nonracemic Tricyclic Cyclobutanes by Asymmetric Intramolecular Michael−Aldol Reaction: Thermodynamic Equilibrium and Activation by Iodonium Ion
作者:Kiyosei Takasu、Megumi Ueno、Masataka Ihara
DOI:10.1021/jo010207q
日期:2001.6.1
Intramolecular Michael-aldol reactions of (-)-phenylmenthyl enoates tethered to cycloalkanone affords tricyclic cyclobutanes with high degrees of diastereochemical control. Kinetic and thermodynamic studies revealed that the Michael-aldol reaction is reversible under conditions in which trimethylsilyl iodide is used in the presence of hexamethyldisilazane at ambient temperature. Different levels of