Selective reductions of cyclic 1,3-diesters by using SmI(2) and H(2)O.
SmI(2)/H(2)O reduces cyclic 1,3-diesters to 3-hydroxyacids with no over reduction. Furthermore, the reagent system is selective for cyclic 1,3-diesters over acyclic 1,3-diesters, and esters. Radicals formed by one-electron reduction of the ester carbonyl group have been exploited in intramolecular additions to alkenes. The ketal unit and the reaction temperature have a marked impact on the diastereoselectivity of the cyclizations. Cyclization cascades are possible when two alkenes are present in the starting cyclic diester and lead to the formation of two rings and four stereocenters with excellent stereocontrol.
Collins
Karl D
KD
School of Chemistry, University of Manchester, Oxford Road, M13 9PL, UK.
Oliveira
Juliana M
JM
Guazzelli
Giuditta
G
Sautier
Brice
B
De Grazia
Sara
S
Matsubara
Hiroshi
H
Helliwell
Madeleine
M
Procter
David J
DJ
D004146:Dioxanes / Q000737:chemistry*; D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry*; D005609:Free Radicals; D006880:Hydroxy Acids / Q000138:chemical synthesis*; D007454:Iodides / Q000737:chemistry; D019163:Reducing Agents / Q000737:chemistry*; D012493:Samarium / Q000737:chemistry; D014867:Water / Q000737:chemistry
D004146:Dioxanes; D004952:Esters; D005609:Free Radicals; D006880:Hydroxy Acids; D007454:Iodides; D019163:Reducing Agents; D014867:Water; D012493:Samarium; C409809:samarium diiodide