Facile Synthesis of Spirocyclic Ketones via Gold(I)-Catalyzed Claisen-Type Rearrangement of Cyclic 8-Aryl-2,7-enyn-1-ols
作者:Ming-Chang P. Yeh、Hui-Fen Pai、Chuen-Yo Hsiow、Yan-Rong Wang
DOI:10.1021/om900833k
日期:2010.1.11
The gold(I)-catalyzed Claisen-type rearrangement of cyclic 8-aryl-2,7-enyn-1-ols proceeds via a cationic allylic vinyl ethergold intermediate to give spirocyclic ketones. The reaction proceeded via attack of the hydroxyl group onto the gold-activated alkynes followed by [3,3]-sigmatropic rearrangement to generate the spirocyclic ketones. This transformation can be applied to the synthesis of aza-
Triflic Acid Catalyzed Synthesis of Spirocycles via Acetylene Cations
作者:Tienan Jin、Masafumi Himuro、Yoshinori Yamamoto
DOI:10.1002/anie.200901771
日期:2009.7.27
acid (TfOH) catalyzed cyclization of alkynyl‐substituted cyclic tertiary alcohols 1 under mild conditions with good control of ring size (see scheme). The method was extended to the synthesis of bridgedbicyclicketones with high stereoselectivity.