Highly regio- and chemoselective ring opening of oxa-bridged piperidinones toward functionalized furanones and piperidines

摘要

Lewis acid mediated competitive ring-opening reactions of N-tosyl-substituted oxa-bridged piperidinone ring systems are demonstrated. A majority of the Lewis acids furnished the regio- and chemoselective reductive ring opening at the C-1-N bond, whereas TiCl4 furnished at the C-1-O bond in the presence of triethylsilane, affording functionalized furanones and dihydroxypiperidines, respectively.