Lactones imides, rearrangement

In 2012, the Fukuyama group reported the total synthesis of the entire family of amathaspiramides, including amathaspiramide F and the C3-epimeric amathaspiramides A-E. This was the first report of the synthesis of any amathaspiramide other than amathaspiramide F. Fukuyama s retrosynthetic analysis was based on a common cyclic imide 23, which could be elaborated to the entire family of natural products (Scheme 8). The cychc imide 23 would be assembled through a key Curtius rearrangement of alkylated lactone 24. 

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