| Autor: |
Russell DA; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. spring@ch.cam.ac.uk., Freudenreich JJ; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. spring@ch.cam.ac.uk., Ciardiello JJ; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. spring@ch.cam.ac.uk., Sore HF; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. spring@ch.cam.ac.uk., Spring DR; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. spring@ch.cam.ac.uk. |
| Abstrakt: |
We describe stereocontrolled semi-syntheses of deguelin and tephrosin, anti-cancer rotenoids isolated from Tephrosia vogelii. Firstly, we present a new two-step transformation of rotenone into rot-2'-enonic acid via a zinc-mediated ring opening of rotenone hydrobromide. Secondly, following conversion of rot-2'-enonic acid into deguelin, a chromium-mediated hydroxylation provides tephrosin as a single diastereoisomer. An Étard-like reaction mechanism is proposed to account for the stereochemical outcome. Our syntheses of deguelin and tephrosin are operationally simple, scalable and high yielding, offering considerable advantages over previous methods. |
