Contrasting diastereofacial selectivity associated with N-phenyltriazolinedione cycloadditions to oxaspirocycloheptatrienes.
[reaction: see text] The cycloaddition of N-phenyltriazolinedione to a pair of spirocyclic cycloheptatrienes featuring a tetrahydrofuran or tetrahydropyran ring is shown to proceed with opposite pi-facial stereoselectivity. In addition, the furan undergoes direct [4+2] cycloaddition to the cycloheptatriene whereas the pyran product is a diazetidine.
Paquette
Leo A
LA
Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA. paquette.1@osu.edu
Webber
Peter
P
Simpson
Iain
I