Abstract
AbstractA short, 5‐step total synthesis of (±)‐3‐demethoxyerythratidinone from a simple pyrrole derivative is described. Features include the formation of gram quantities of a key tricylic aziridine from a challenging photochemical cascade reaction through the use of flow photochemistry. The final step involved a highly unusual Heck cyclization whereby ligand control enabled efficient formation of the natural product in 69 % yield from the minor isomer present in an equilibrating mixture of labile enamines.
Highlights
The alkaloid (+)-3-demethoxyerythratidinone 1 is one of over 100 natural products produced by the Erythrina genus of flowering plants.[1]
Since the first total synthesis of 1 by Tsuda in 1984,[2] this tetracyclic alkaloid has been used by others in order to demonstrate the utility of various synthetic methodologies.[3]
A very elegant synthesis was recently reported by Reisman, where chiral sulfinyl imine chemistry was used to control the stereochemistry of the key quaternary center,[3d] giving (À)-3-demethoxyerythratidinone in just six steps overall (Figure 1)
Summary
The alkaloid (+)-3-demethoxyerythratidinone 1 is one of over 100 natural products produced by the Erythrina genus of flowering plants.[1]. We report a short total synthesis of (Æ)-1 utilizing a highly unusual and selective, ligand controlled intramolecular Heck-reaction onto one of a pair of equilibrating enamine intermediates. Upon cleavage of the tert-butyl ester the resultant acid underwent spontaneous decarboxylation to generate the isolable, but labile enamine (Æ)-14 in excellent yield.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
