Studies towards the synthesis of cartorimine

ORGN 183

Rui Chen, rui.chen@lincoln.ox.ac.uk, Jack E Baldwin, jack.baldwin@chem.ox.ac.uk, and Victor Lee. Department of chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, United Kingdom
Carthamus trinctorius L. (Compositae) is a widely used traditional Chinese medicine having the function of promoting blood circulation.[1] Cartorimine (1) (Figure 1), a new cycloheptenone oxide derivative, has been obtained from the flower petals of C. trinctorius.[2]

The retrosynthetic analysis is based on an intramolecular approach. It begins with fully protected Cartorimine, which could be accessed by 1,4-addition of the appropriate aryl lithium to the protected ketone. This compound could be gained from our proposed key intermediate, which is synthesized by an intramolecular 1,3-dipolar cycloaddition.

Another retrosynthetic analysis is based on an intermolecular cycloaddition approach to the core cycloheptenone structure. It begins with fully protected Cartorimine, which could be accessed by 1,4-addition of the appropriate aryl lithium to the protected ketone. This compound could be gained from function group transformations of the intermediate, which would be synthesized by reaction between the acetate and some acetylenic compounds.