Asymmetric routes to the trisporic acids via chiral bicyclic lactams
摘要:
Two synthetic approaches to the title compounds using the chiral non-racemic lactam 3 via additions to the lactam carbonyl lead to the requisite chiral cyclohexen-2-ones. (C) 1999 Elsevier Science Ltd. All rights reserved.
An Unusual Access to Medium Sized Cycloalkynes by a New Gold(I)-Catalysed Cycloisomerisation of Diynes
作者:Yann Odabachian、Xavier F. Le Goff、Fabien Gagosz
DOI:10.1002/chem.200901312
日期:2009.9.14
Dual reactivity of alkynes: The gold(I)‐catalysed cycloisomerisation of 1,9‐ and 1,10‐diynes allows the efficient synthesis of medium‐sized cycloalkynes. This rare alkyne–alkyne coupling is proposed to proceed by the nucleophilic addition of a gold acetylide to a gold(I)‐activated alkyne.
A New Co<sub>2</sub>(CO)<sub>8</sub>-Mediated Tandem [5 + 1]/[2 + 2 + 1]-Cycloaddition Reaction: A One-Pot Synthesis of Tricyclic δ-Lactones from <i>cis</i>-Epoxy Ene-ynes
作者:Arjan Odedra、Chang-Jung Wu、Reniguntala J. Madhushaw、Su-Lein Wang、Rai-Shung Liu
DOI:10.1021/ja0346633
日期:2003.8.1
In the presence of Co2(CO)8 and CO, cis-epoxyalkynes bearing a tether olefin undergo a tandem [5 + 1]/[2 + 2 + 1]-cycloaddition to give tricyclic delta-lactones efficiently in a one-pot operation. The reaction mechanism is proposed to involve a cobalt-coordinated cyclic allene species.