Jozef Stec
Marshall B. Ketchum University, USA
Title: Transition metal-assisted total synthesis of natural products
Biography
Biography: Jozef Stec
Abstract
Chemical transformations mediated by transition metals play pivotal role in modern organic chemistry. New reaction development and total synthesis of complex natural products are only a few examples of harnessing the organometallic chemistry. Organozirconium chemistry was successfully utilized in the total synthesis of natural products as exemplified by the recently reported total synthesis of (+)-mucosin. The developed methodology utilized the one-pot two-step zirconocene-mediated co-cyclisation of triene followed by insertion of silylcarbenoid generated in situ, to give the expanded zirconacycle. Protonolysis of zirconacycle followed by the modified Flaming-Tamao oxidation gave the bicyclic alcohol which was oxidized to its corresponding aldehyde by using the Swern protocol. Takaiolefination provided the protected alcohol which was converted to the corresponding carboxylic acid via TBAF deprotection and PDC oxidation. Esterification using diazomethane procedure gave the methyl ester of (+)-mucosin, which is the dextrorotatory enantiomer of the naturally isolated ( )-mucosin methyl ester.