Unusual endoperoxide isomerizations: a convenient entry into 2-vinyl-2-cyclopentenones from saturated fulvene endoperoxides
摘要:
An unusual peroxide base-promoted isomerization is uncovered. Saturated endoperoxides derived from fulvenes give rise to 2-vinyl-2-cyclopentenones upon treatment with DBU in CH2CL2 in a one-pot reaction. This methodology is applied to a convenient synthesis of dihydrojasmone. Moreover, functional groups placed on the side chain at C-6 participate in the base-catalyzed isomerizations via conjugate attack at the enone moiety to give 2-cyclopentenones carrying oxygen heterocycles at C-2. (c) 2006 Elsevier Ltd. All rights reserved.
Pyrrolidine-catalyzed reactions between .alpha.,.beta.-unsaturated carbonyl compounds and cyclopentadiene: a convenient approach to 1,2- and 1,5-dihydropentalenes
Zirconocene Functional Group Chemistry: Photochemical [4+4] Cycloaddition of Isoprenyl Sidechains to the Bent Metallocene Framework
作者:Ingo Greger、Gerald Kehr、Gerhard Erker
DOI:10.1002/ejic.201000432
日期:2010.10
hexamethyldisilylamide. Transmetallation to zirconium or hafnium gave the respective bis(4-isoprenyl-Cp)MCl 2 and bis(1-isoprenyl-Cp)MCl 2complexes 7a,b and 8a,b, respectively. Upon photolysis, the (4-isoprenyl-Cp) 2 ZrCl 2 and -HfCl 2complexes 7a, 8a underwent rapid intramolecular [4+4] cycloaddition reactions to yield the cyclooctadienylene-bridged ansa-metallocenes 9a, 10a in high yields.