Stereocontrolled 1,3-dipolar cycloadditions using Oppolzer's camphor sultam as the chiral auxiliary for carbonyl stabilized azomethine ylides

摘要

Two complementary approaches to substituted pyrrolidines via stereocontrolled 1,3-dipolar cycloaddition reactions of chiral azomethine ylides are desctibed.In one approach,chiral azomethine ylides were generated by thermolysis of aziridine carboxylate sultams and trapped with a variety of dipolarophiles to give good yields of the corresponding cycloadducts.In the second approach,chiral azomethine ylides were generated from glycyl sultams by 'imine tautomerization' and trapped with dipolarophiles to give good yields of the corresponding cycloadducts.