Spiro- and bridged-ring forming electrophile induced -> grime -> nitrone cycloaddition cascades. Multiplication of chirality

Article abstract of DOI:10.1016/S0040-4039(97)01255-0

Electrophile induced 6-exo-trig spirocyclisation of oximes onto 5-, 6- or 7-membered cycloalkenes occurs stereo- and regio- specifically in good yield. Bridged - ring forming cyclisations creating bicycle-[3.3.1]- and bicyclo-[3.2.1]-ring systems also occur in good yield. Chiral bridged-ring systems have been synthesised, via the latter processes, that involve multiplication of chiral centres from one to six and seven in one pot reactions.