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Updated: Aug 18, 2026

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography
Published on: May 16, 2014
Aziridine-Allylsilane-Mediated Total Synthesis of (-)-Yohimbane
Stephen C. Bergmeier1, Punit P. Seth
1Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy and the Comprehensive Cancer Center, The Ohio State University, 500 West 12th Avenue, Columbus, Ohio 43210-1291.
Abstract:
A total asymmetric synthesis of (-)-yohimbane and ent-alloyohimbane is reported. The synthesis utilizes a novel aziridine-allylsilane cyclization reaction as a key step in the synthesis. Treatment of optically pure aziridine-allylsilane 16 with BF(3).OEt(2) provided a mixture of aminomethyl substituted carbocycles trans-20a and cis-20b in excellent yield and modest diastereoselectivity (trans/cis 3:1). Alkylation of the tosylamide followed by oxidation of the olefin in 20 provided the lactam 38, which was converted to (-)-yohimbane and ent-alloyohimbane by a Bischler-Napieralski reaction. The synthesis provided (-)-yohimbane in eight steps and 24% overall yield (from 16).
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