Total Synthesis of the Putative Structure of Lucentamycin A
作者:Ujjwal Pal、Sujeewa Ranatunga、Yamuna Ariyarathna、Juan R. Del Valle
DOI:10.1021/ol902251c
日期:2009.11.19
A rapid and stereoselective enolate-Claisen rearrangement provides access to the 4-ethylidene-3-methylproline (Emp) subunit of lucentamycin A. Synthesis of the putativestructure of the cytotoxic natural product suggests the need for structural revision.
Ireland-Claisen Rearrangement of 6-Methylene-1,4-oxazepan-2-ones
作者:Gints Smits、Artis Kinens、Ronalds Zemribo
DOI:10.1002/ejoc.201500918
日期:2015.10
The Ireland–Claisenrearrangement of 6-methylene-1,4-oxazepan-2-one-derived boron enolates leads to stereochemically defined, synthetically useful 4-(E)-ethylidene prolines. Detailed computational and experimental studies explain the stereochemical outcome of this transformation and suggest an unusual double-chelated transition state that involves two boron atoms. The scope of the method is also explored