Abstract

A novel procedure is described for the formation of methyl and vinyl substituted oxacycle fused uracil derivatives. Ring closing metathesis and enyne metathesis of dienes and enynes respectively proceeded smoothly under nitrogen atmosphere at room temperature in the presence of well defined catalyst (first generation Grubbs catalyst) to afford the substituted oxepin derivatives in good yields. The substrates were prepared by the Claisen rearrangement and subsequent alkylation of the rearranged products.

Keywords: 1,3-dimethyl-5-hydroxyuracil, Claisen rearrangement, ring closing metathesis, enyne metathesis, oxepin, oxocin