Discovery of a Phosphine-Mediated Cycloisomerization of Alkynyl Hemiketals: Access to Spiroketals and Dihydropyrazoles via Tandem Reactions
作者:Jaideep Saha、Chris Lorenc、Bikash Surana、Mark W. Peczuh
DOI:10.1021/jo3001854
日期:2012.4.20
functionality (R2) on the cyclic keto enol ether, a rapid and facile dimerization occurs, giving spiroketal products. When the enone is substituted (i.e., R2 = Ph), the cyclic keto enol ether is sufficiently stable so that it can be isolated; it can then be further reacted in the same pot to provide the corresponding dihydropyrazoles. Both the spiroketal and dihydropyrazole products arise by a tandem reaction