Total Synthesis and Structural Revision of Greensporone F and Dechlorogreensporone F

• Published in: Journal of organic chemistry Vol. 85; no. 19; pp. 12418 - 12429
• Main Authors: Gaddam, Janardhan, Reddy, Aedula Vishnu V, Sarma, Akella V. S, Yadav, Jhillu S, Mohapatra, Debendra K
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02-10-2020
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/acs.joc.0c01644

The first asymmetric total syntheses of the real isolation product (2S,5R,8R)-greensporone F and (2S,5R,8R)-dechlorogreensporone F, 14-membered resorcylic acid lactones with a cis-2,5-disubstituted tetrahydrofuran ring system, was accomplished. The synthesis features a late-stage Lewis acid-catalyzed stereoselective intramolecular oxa-Michael reaction, E-selective ring-closing metathesis, De Brabander’s esterification, and Jacobsen’s hydrolytic kinetic resolution as the key steps. Synthesis of both real isolation and erroneously proposed structure necessitated the revision of the absolute configuration of greensporone F and dechlorogreensporone F. The erroneous representation of (2S,5S,8S)-configuration in greensporone F and dechlorogreensporone F was assigned to be (2S,5R,8R) by comparison with the NMR data and specific rotation of the synthetic compounds with that of the reported data.