Direct Kinetic Formation of Nonanomeric [6.5]-Spiroketals in Aqueous Media
作者:Daniele Castagnolo、Irene Breuer、Petri M. Pihko
DOI:10.1021/jo702022u
日期:2007.12.1
precursors under acid catalysis was studied using four differently substituted systems. In all cases, the exclusive formation of the anomeric isomer was observed under equilibrating conditions. However, the formation of the nonanomeric spiroketal isomer was observed if the reaction was performed under kinetic conditions using an appropriately tuned acid. Water had a dramatic accelerating effect on the spiroketalization