Samarium(II)-mediated reactions of gamma,delta-unsaturated ketones. Cyclization and fragmentation processes.
[reaction: see text] On treatment with samarium(II) iodide, gamma,delta-unsaturated ketones undergo very different processes depending upon the nature of the reaction conditions. Employing samarium(II) iodide and MeOH, functionalized syn-cyclopentanol products are obtained stereoselectively. Mechanistic studies suggest that this cyclization occurs via a sequential reduction/intramolecular aldol reaction. With samarium(II) iodide and HMPA, products of a 4-exo-trig cyclization and of an interesting fragmentation reaction are observed.
Hutton
Thomas K
TK
Department of Chemistry, The Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK.
Muir
Kenneth
K
Procter
David J
DJ