A Protecting Group Free Synthesis of (±)-Neostenine via the [5 + 2] Photocycloaddition of Maleimides
The Journal of Organic Chemistry2008Vol. 73(17), pp. 6497–6505
Citations Over TimeTop 10% of 2008 papers
Michael Lainchbury, Marcus I. Medley, Piers M. Taylor, Paul R. Hirst, Wolfgang Döhle, Kevin I. Booker‐Milburn
Abstract
A concise, linear synthesis of the Stemona alkaloid (+/-)-neostenine is reported. Key features include an organocopper-mediated bislactone C2-desymmetrization for the stereoselective construction of the cyclohexane-lactone C,D-rings. The assembly of the fused pyrrolo[1,2-a]azepine core was achieved by application of a [5 + 2] maleimide photocycloaddition. A custom FEP flow reactor was used to successfully overcome the scale limitations imposed by a classical immersion well batch reactor. The synthesis was completed in 14 steps from furan, in 9.5% overall yield, without the use of any protecting groups.
Related Papers
- → Local Desymmetrization through Diastereotopic Group Selection: An Enabling Strategy for Natural Product Synthesis(2017)37 cited
- → Asymmetric Desymmetrization: Simultaneous Stereocontrol of Multi-chiral Centers.(2002)24 cited
- → 5.23 Desymmetrization of meso Anhydride(2012)1 cited
- → Chiral DMAP Catalyzed Desymmetrization of meso Primary Diols(2014)
- → Trost Desymmetrization(2010)