Seven-membered ring heterocydes

Many of these heterocydes are commerdally available. They arise from petroleum as source, except LA. Methyl-substituted seven-membered ring carbonates (7CCs), namely 4-methyl-and 5-methyl-l,3-dioxepan-2-one (R-Me7CC and p-Me7CC), have been synthesized by cydization of the corresponding a,[Pg.71]

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