Asymmetric Total Synthesis of (−)-Juvabione via Sequential Ir-Catalyzed Hydrogenations
作者:Jia Zheng、Cristiana Margarita、Suppachai Krajangsri、Pher G. Andersson
DOI:10.1021/acs.orglett.8b02405
日期:2018.9.21
centers via sequential Ir-catalyzed hydrogenations. The first center is generated by hydrogenation of a styrene-type double bond (99% ee). The successive monohydrogenation of a diene intermediate constitutes the key step, granting high levels of regio- and stereocontrol (94:6 dr). This novel strategy allowed the preparation of (−)-juvabione from simple starting materials in 9 steps and 17% total yield.
Synthesis of juvabione in short steps in a high overall yield has been achieved via the chemoselective reduction with Hantzsch ester (HEH) in the presence of silica gel as a key step.
The novel tandem process Diels-Alderreaction/Ireland-Claisen rearrangement shows a high diastereoselectivity for the Ireland-Claisen rearrangement starting from the endo-product of the Diels-Alderreaction. Based on this mechanistic knowledge, the novel tandem process could be applied to the synthesis of rac-juvabione.