Synfacts 2019; 15(04): 0335
DOI: 10.1055/s-0037-1612377
Synthesis of Natural Products and Potential Drugs
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Eburnane-Type Alkaloids

Erick M. Carreira
Michael A. Imhof
Li G, Piemontesi C, Wang Q, Zhu J. * Ecole Polytechnique Fédérale de Lausanne, Switzerland
Stereoselective Total Synthesis of Eburnane-Type Alkaloids Enabled by Conformation-Directed Cyclization and Rearrangement.

Angew. Chem. Int. Ed. 2019;
58: 2870-2874
Further Information

Publication History

Publication Date:
19 March 2019 (online)



Zhu and co-workers present their recent efforts to access eburnane-type alkaloids using a highly divergent approach. The presented route features an α-iminol rearrangement to access the trans-fused core in intermediate D. The conformational bias allowed to close the remaining six-membered ring of the eburnane core in a diastereoselective fashion. The divergent design of the route uses key intermediates D and E to access four different eburnane alkaloids with good yields.



α-Iminol rearrangement of C led to key intermediate D. Oxidative cleavage of the diol and reduction yielded hexacyclic aminal F as a single dia­stereomer. Lewis acid induced 1,2-alkyl shift of F furnished (±)-terengganensine B. Reduction to alcohol G and Brønsted acid mediated rearrangement allowed synthesis of (±)-larutensine. Oxidation of diol D to the corresponding diketone and subsequent oxidative bond cleavage gave pentacyclic amide I. (±)-Melokhanine E was obtained in five ­additional steps and was then converted into (±)-eburnamonine by means of an aza-pinacol ­rearrangement.