Selective Synthesis of Cyclooctanoids by Radical Cyclization of Seven-Membered Lactones: Neutron Diffraction Study of the Stereoselective Deuteration of a Chiral Organosamarium Intermediate.
Seven-membered lactones undergo selective SmI2 -H2 O-promoted radical cyclization to form substituted cyclooctanols. The products arise from an exo-mode of cyclization rather than the usual endo-attack employed in the few radical syntheses of cyclooctanes. The process is terminated by the quenching of a chiral benzylic samarium. A labeling experiment and neutron diffraction study have been used for the first time to probe the configuration and highly diastereoselective deuteration of a chiral organosamarium intermediate.
School of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
Xavier
X
Just-Baringo
School of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
Jemma
J
Clark
ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK.
Matthias J
MJ
Gutmann
School of Chemistry, University of Manchester, Manchester, M13 9PL, UK. david.j.procter@manchester.ac.uk.
David J
DJ
Procter
cyclization; cyclooctanes; neutron diffraction; radicals; samarium diiodide