Domino Reactions That Combine an Azido-Schmidt Ring Expansion with the Diels−Alder Reaction
摘要:
The combination of the intramolecular Schmidt reaction with the Diels-Alder reaction provides expedient access to a variety of heterocycles. Two different modes of reaction planning are presented. In one, the azide and ketone moieties necessary for the intramolecular Schmidt reaction originate on different molecules that are reacted and subsequently undergo a ring-adjustment step. Alternatively, an azido ketone can be used provided the ketone is deactivated by its presence in an enone.
Syntheses of the <i>Stemona</i> Alkaloids (±)-Stenine, (±)-Neostenine, and (±)-13-Epineostenine Using a Stereodivergent Diels–Alder/Azido-Schmidt Reaction
作者:Kevin J. Frankowski、Jennifer E. Golden、Yibin Zeng、Yao Lei、Jeffrey Aubé
DOI:10.1021/ja800574m
日期:2008.5.1
A tandem Diels-Alder/azido-Schmidt reaction sequence provides rapidaccess to the core skeleton shared by several Stemona alkaloids including stenine, neostenine, tuberostemonine, and neotuberostemonine. The discovery and evolution of inter- and intramolecular variations of this process and their applications to total syntheses of (+/-)-stenine and (+/-)-neostenine are described. The stereochemical
The combination of the intramolecular Schmidt reaction with the Diels-Alder reaction provides expedient access to a variety of heterocycles. Two different modes of reaction planning are presented. In one, the azide and ketone moieties necessary for the intramolecular Schmidt reaction originate on different molecules that are reacted and subsequently undergo a ring-adjustment step. Alternatively, an azido ketone can be used provided the ketone is deactivated by its presence in an enone.