Scaffold modification epoxidation reactions

An exploration of structural modifications on the activity of prolinol catalysts has been published <06T12264>. More electron-rich aromatic rings on the prolinol scaffold improve the activity in the epoxidation of a, 3-enones. The reaction of 10 with an enone and f-BuOOH provides the epoxy-ketones with moderate levels of enantioselectivity. 

Modification reactions create the enormous diversity of plant natural products, providing new molecules with different biological activities from the basic scaffolds outlined above. The plant kingdom contains a large number of enzymes that catalyze hydroxylation, epoxidation, aryl migration, glyco-sylation, methylation, sulfation, acylation, pre-nylation, oxidation and reduction of secondary metabolite skeletons, examples of which are reviewed below, and illustrated, for phenylpropa-noid and flavonoid biosynthesis, in Fig- 5. Figure 6... 

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