Photochemical Rearrangement of <i>N</i>-Chlorolactams: A Route to <i>N</i>-Heterocycles through Concerted Ring Contraction
作者:Dana K. Winter、Alexandre Drouin、Jean Lessard、Claude Spino
DOI:10.1021/jo100181h
日期:2010.4.16
We report a novel ringcontraction allowing the direct conversion of N-chlorolactams to their corresponding ring-contraction N-heterocycles upon photolysis. Results show that the rearrangement occurs with a variety of N-chlorolactams and that the greater the substitution at the migrating carbon, the greater the yield of product. Importantly, stereochemistry at the migrating carbon is conserved in the
Photochemical Rearrangement of <i>N</i>-Mesyloxylactams: Stereospecific Formation of <i>N</i>-Heterocycles
作者:Alexandre Drouin、Dana K. Winter、Simon Pichette、Samuel Aubert-Nicol、Jean Lessard、Claude Spino
DOI:10.1021/jo101805q
日期:2011.1.7
N-Mesyloxylactams undergo an efficient ring-contraction to N-heterocycles of various ring sizes. Yields increase with the degree of substitution α to the carbonyl. The stereochemical information of a chiral migrating carbon is conserved making this reaction a synthetically useful complement to the well-known Hofmann, Curtius, Lossen, and Schmidt rearrangements.