Mechanism of the Acid-Mediated Thermal Fragmentation of 5-Spirocyclobutane-isoxazolidines
作者:Franca M. Cordero、Carolina Vurchio、Alberto Brandi、Remo Gandolfi
DOI:10.1002/ejoc.201100621
日期:2011.10
Protonation at the nitrogen of 5-spirocyclopropane-isoxazolidines induces clean thermal rearrangement/fragmentation to β-lactams and ethylene. Under the same conditions, homologous 5-spirocyclobutane-isoxazolidines undergo unselective fragmentation to give cyclobutyl derivatives through a completely different mechanism. Experimental data and DFT calculations show that the process is initiated with