Total Syntheses of Calyciphylline A-type Alkaloids (−)-10-deoxydaphnipaxianine A, (+)-daphlongamine E, and (+)-calyciphylline R via late-stage diallylic alcohol rearrangements

06 June 2022, Version 1

Abstract

Consisting of more than 350 isolated members, the Daphniphyllum alkaloids possess complicated, polycyclic, and often caged skeletons along with diverse, interesting biological profiles. Among this natural product family, the representative calyciphylline A-type subfamily has triggered particular interest from the organic synthesis community. In this paper, we wish to report divergent total syntheses of three calyciphylline A-type alkaloids, namely (−)-10-deoxydaphnipaxianine A, (+)-daphlongamine E, and (+)-calyciphylline R. Our work highlights an efficient, divergent strategy via late-stage diallylic alcohol rearrangements, including an unprecedented oxidative Nazarov electrocyclization using an unfunctionalized diallylic alcohol and, an unusual, transannular allylic alcohol rearrangement. Other key transformations in our approach including an nitrile hydration using a highly efficient “donor-acceptor” platinum catalyst, an intramolecular Heck coupling and an intramolecular, regioselective pinacol coupling. Moreover, the power of selective amide reductions has also been showcased by novel and classic tactics. The strategies and methods used in our approach might provide further inspiration for natural product synthesis. Particularly, the novel oxidative Nazarov electrocyclization should be valuable in the chemical synthesis of other cyclopentenone-containing small molecules.

Content

Supplementary materials

Supporting Information
Supplementary Information for Total Syntheses of Calyciphylline A-type Alkaloids (−)-10-deoxydaphnipaxianine A, (+)-daphlongamine E, and (+)-calyciphylline R via late-stage diallylic alcohol rearrangements

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.