~1H NMR-based kinetic and mechanistic study of unusual skeletal rearrangements of a spirobornyl tosylate derivative

摘要

~1H NMR analysis of the kinetics of skeletal rearrangement of optically pure 3,3-xylyl-2-exo-bornyl tosylate in CDCl_3 indicates the operation of tandem autocatalytic and pseudo-first-order transformations, leading sequentially to a pair of isomeric camphene derivatives and involving partial racemization. Changing the solvent system has been shown to permit the chemoselective isolation of either of the isomeric camphenes. Analysis of the kinetics of skeletal rearrangement of optically pure 3,3-xylyl-2-exo-bornyl tosylate 4 in CDCl_3 reveals tandem autocatalytic and pseudo-first-order transformations, affording sequentially a pair of isomeric camphene derivatives (5 and 6) and involving partial racemisation. Changing the solvent permits chemoselective isolation of either of the isomeric camphenes. Analysis of the kinetics of skeletal rearrangement of optically pure 3,3-xylyl-2-exo-bornyl tosylate 4 in CDCl3 reveals tandem autocatalytic and pseudo-first-order transformations, affording sequentially a pair of isomeric camphene derivatives (5 and 6) and involving partial racemisation. Changing the solvent permits chemoselective isolation of either of the isomeric camphenes.