Rearrangement of Isoxazoline-5-spiro Derivatives. 5. Diastereofacial Selectivity in the Cycloaddition of Substituted Five-Membered Cyclic Nitrones and Methylenecyclopropanes. Srereoselective Synthesis of 3,5-Substituted Indolizidinones

Article abstract of DOI:10.1021/jo00293a018

Substituted five-membered cyclic nitrones 1-3 cycloadd to substituted methylenecyclopropanes 4 and 5 with high diasrereofacial selectivity, through anti-anti transition states, to produce regioisomeric hexahydrospiro