High chelation control of three contiguous stereogenic centers in the Reformatsky reactions of indium enolates with alpha-hydroxy ketones: unexpected stereochemistry of lactone formation.
Indexed on: 30 Jun '06Published on: 30 Jun '06Published in: Organic Letters
Abstract
[reaction: see text] A boat-type of chelated bicyclic transition state involving highly diastereoselective construction of three contiguous stereogenic centers in the Reformatsky reaction of indium enolates with alpha-alkoxy/hydroxy ketones is proposed. alpha-Hydroxy ketones with indium enolates furnished highly diastereoselective lactones, while alpha-alkoxy ketones gave acyclic esters in moderate selectivities. X-ray structure analyses of key products unequivocally revealed the unexpected stereochemistry of products and the reaction pathway.
