Work

Enantioselective Synthesis of Both Epimers at C-21 in the Proposed Structure of Cytotoxic Macrolide Callyspongiolide

Year: 2016

Type: article

Abstract: Both epimers at C-21 in the proposed structure of (+)-callyspongiolide have been synthesized in a convergent and enantioselective manner. The 14-membered macrolide with a sensitive C2-C3 cis-olefin functionality was installed by a Yamaguchi macrolactonization of hydroxyl alkynoic acid followed by hydrogenation over Lindlar's catalyst. The C5 methyl stereocenter was constructed by a ring-closing olefin metathesis followed by addition of methyl cuprate to an α,β-unsaturated δ-lactone. Other key reactions are chiral Corey-Bakshi-Shibata (CBS) reduction and Sonogashira coupling to conjoin the macrocyclic core and side chain.

Source: Organic Letters

DOI: 10.1021/acs.orglett.6b01523

Authors: Arun K. Ghosh, Luke A. Kassekert

Institution: Purdue University West Lafayette

Language: English

Topic: Organic Chemistry Synthesis Methods

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: Purdue University, National Institutes of Health, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases

Award: DESIGN AND SYNTHESIS OF NONPEPTIDE PROTEASE INHIBITORS