作者:Jonathan W. Burton、Andrew B. Holmes、S. Y. Mak、Neil R. Curtis、Andrew N. Payne、Miles S. Congreve、Craig L. Francis
DOI:10.1055/s-2005-918470
日期:——
A synthesis of the halogenated medium-ring ether natural product (+)-obtusenyne is reported utilizing a Claisen rearrangement and an intramolecular hydrosilation as key steps.
作者:S. Y. Frankie Mak、Neil R. Curtis、Andrew N. Payne、Miles S. Congreve、Andrew J. Wildsmith、Craig L. Francis、John E. Davies、Sofia I. Pascu、Jonathan W. Burton、Andrew B. Holmes
DOI:10.1002/chem.200701567
日期:2008.3.17
An enantioselective synthesis of the halogenated medium-ring ether natural product (+)-obtusenyne is reported which uses the ring expansion of a seven-membered ketene acetal by means of a Claisen rearrangement to construct the core nine-membered oxygen heterocycle. The trans substituents across the ether linkage were established by using a transition-metal-catalyzed intramolecular hydrosilation reaction
Regiochemical control of the ring opening of 1,2-Epoxides by means of chelating processes. 11. Ring opening reactions of aliphatic mono- and difunctionalized cis and trans 2,3- and 3,4-Epoxy Esters
The regiochemical outcome of the ring opening of 1,2-epoxides through chelation processes assisted by metal ions, was verified in the azidolysis of simple aliphatic cis and trans 2,3- and 3,4-epoxy esters and in the corresponding derivatives bearing an ether functionality (OBn) in an allylic relationship to the oxirane ring. The results indicate that the behavior of these epoxides is influenced both by the opening conditions (standard or metal-assisted) and the promoting metal salt [LiClO4 or Mg(ClO4)(2)].