A second-generation synthesis of the C1-C28 portion of the altohyrtins (spongistatins) |
| |
Authors: | Hubbs Jed L Heathcock Clayton H |
| |
Institution: | Center for New Directions in Organic Synthesis, Department of Chemistry, University of California, Berkeley, California 94720, USA. |
| |
Abstract: | A practical second-generation synthesis of an advanced intermediate in our total synthesis of altohyrtin C (spongistatin 2) has been developed. A new approach to the C1-C15 (AB) portion features a vinyllithium addition to an aldehyde followed by a palladium-catalyzed allylic reduction to install the troublesome C13-C15 segment. Our general approach to the C16-C28 (CD) spiroketal has been retained, but some improvements have been made. Most notably, the kinetically controlled CD-spiroketalization reaction now proceeds in high yield with excellent diastereoselection. This new strategy uses the anti-aldol coupling used in our first-generation synthesis to join AB and CD fragments. A total of 9.6 g of intermediate 57 has been produced using this improved route. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|