Synlett 2018; 29(13): 1683-1692
DOI: 10.1055/s-0037-1610152
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© Georg Thieme Verlag Stuttgart · New York

Tackling the Challenge of the Total Synthesis of Periploside A

Xiaheng Zhang
State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, P. R. of China   Email: byu@sioc.ac.cn
,
Biao Yu*
State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, P. R. of China   Email: byu@sioc.ac.cn
› Author Affiliations
The financial support from the National Natural Science Foundation of China (21432012 & 21621002), the Strategic Priority Research ­Program of the Chinese Academy of Sciences (XDB20020000), and the K. C. Wong Education Foundation is acknowledged.
Further Information

Publication History

Received: 06 March 2018

Accepted after revision: 13 April 2018

Publication Date:
28 May 2018 (online)


Abstract

Periploside A is the prototypical congener of the pregnane glycosides occurring in the Chinese medicinal plant Periploca sepium, featuring a unique seven-membered formyl acetal bridged spiro-­orthoester (FABO) sugar linkage and potent immunosuppressive activities. This account details our efforts on the stereoselective construction of the FABO motif that has led to a successful total synthesis of peri­ploside A.

1 Introduction

2 Attempts at Construction of the FABO Motif

2.1 Intermolecular Condensation and Transacetalation

2.2 Intramolecular Hydrogen Atom Transfer (HAT) Reaction

3 Synthesis of the FABO Motif Bearing the Unnatural Anomeric Configuration

4 Synthesis of the FABO Motif Bearing the Natural Anomeric ­Configuration

4.1 Unsuccessful Attempts

4.2 Final Solution

5 Conclusion