Mild and rapid method for the generation of o-quinone methide intermediates. Synthesis of puupehedione analogues
作者:Alejandro F. Barrero、José F. Quílez del Moral、M. Mar Herrador、Pilar Arteaga、Manuel Cortés、Julio Benites、Antonio Rosellón
DOI:10.1016/j.tet.2006.04.004
日期:2006.6
A route to simpler analogues to bioactive puupehedione derivatives involving a hetero Diels–Alder cycloaddition of a o-quinonemethide is described. These intermediate species are generated via fluoride-induced desilylation of silyl derivatives of o-hydroxybenzyl iodides. Remarkable short reaction times and very mild experimental conditions are the main features of this method.
Benzynes were generated from o-(trimethylsilyl)phenols using nonafluorobutanesulfonyl fluoride (NfF) by a domino process, i.e., the nonaflation of the phenolic hydroxyl group of o-(trimethylsilyl)phenols by NfF followed by the attack of the produced fluoride ion on the trimethylsilyl group. The generated benzyne immediately underwent various reactions to give polysubstituted benzenes.
An Efficient Stereoselective Synthesis of Cytotoxic 8-Epipuupehedione
作者:Veronica Armstrong、Alejandro F. Barrero、Enrique J. Alvarez-Manzaneda、Manuel Cortés、Beatriz Sepúlveda
DOI:10.1021/np030029r
日期:2003.10.1
An efficient and highly stereoselectivesynthesis of cytotoxic 8-epipuupehedione (1b) was achieved starting from natural (-)-drimenol (6). The key step to obtain stereoselectivity was the simultaneous demethylation and oxidation of the dihydrobenzopyran methoxy derivatives 10a and 10b.