Synthetic Applications of Electrochemically Produced α-Methoxyamides. Part 2) Oxidation of Hydroxyproline Derivatives

Article abstract of DOI:10.1002/hlca.19860690727

The electrochemical methoxylation of N-acetyl-4-hydroxyproline esters has been investigated.Both the free alcohol 3 and the corresponding 4-acetoxy derivative 4 as well as the cis-4-acetoxyproline 17 are methoxylated anodically preferentially at C(5), giving a mixture of stereoisomeric methoxy compounds.These mixtures can be used for further substitution as exemplified by the allylation of the methoxylated 4-acetoxy derivatives, giving substitution products preferentially trans to the acetoxy group although with low selectivity.The low selectivity is discussed in terms of kinetic vs. thermodynamic control.