[3+ 2] Cycloaddition of Nonstabilized Azomethine Ylides. 7. Stereoselective Synthesis of Epibatidine and Analogues

G Pandey, TD Bagul, AK Sahoo

Index: Pandey, Ganesh; Bagul, Trusar D.; Sahoo, Akhil K. Journal of Organic Chemistry, 1998 , vol. 63, # 3 p. 760 - 768

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Citation Number: 92

Abstract

Epibatidine (1) is synthesized by employing a [3+ 2] cycloaddition strategy as a key step via nonstabilized azomethine ylide 10, generated by one-electron oxidative double desilylation of N-benzyl-2, 5-bis (trimethylsilyl) pyrrolidine (12). Cycloaddition of 10 with trans-ethyl-3-(6- chloro-3-pyridyl)-2-propenoate (22a) gives 26 in which the 6-chloro-3-pyridyl moiety is endo- oriented. Decarboxylation followed by debenzylation gives unnatural epimer 30 of 1. The ...