Metal-mediated alkynediol cycloisomerization: first and second generation formal total syntheses of didemniserinolipid B

TitleMetal-mediated alkynediol cycloisomerization: first and second generation formal total syntheses of didemniserinolipid B
Publication TypeJournal Article
Year of Publication2013
AuthorsDas, S, Induvadana, B, Ramana, CV
JournalTetrahedron
Volume69
Issue7
Pagination1881-1896
Date PublishedFEB
ISSN0040-4020
KeywordsAlkynol-cycloisomerization, Bicyclic ketal, Gold catalysis, Palladium catalysis, Zipper reaction
Abstract

A formal total synthesis of didemniserinolipid B was developed by employing a regioselective metal-mediated 6-endo-dig alkynol-cycloisomerization reaction. Two routes for the synthesis of key Burke's intermediate have been developed. Our initial approach involved the introduction of a C-17-allcynol followed by Pd-mediated cycloisomerization and then coupling with the serinol unit prior to the introduction of an alpha,beta-unsaturated ester unit through selective oxidation of 1 degrees-OH followed by a two-carbon Wittig homologation. Alternatively, the second generation strategy featuring the serinol coupling with the C-17-alkynol followed by alkyne addition to the epoxide and subsequent Au-mediated cycloisomerization of an acetonide protected alkynediol unit has been executed. This approach has avoided several late stage protection-deprotection events. (C) 2012 Elsevier Ltd. All rights reserved.

DOI10.1016/j.tet.2012.12.045
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)2.817
Divison category: 
Organic Chemistry