Cyclophane,XIV : darstellung polymethylierter [2.2]paracyclophane

Starting from 4, 5, 12, 13-tetrakis(methoxycarbonyl)2.2]paracyclophane ($\text{1}$), the penta-($\text{4}$), hexa-($\text{6a}$–$\text{c}$), hepta-($\text{7}$), and octamethyl-($\text{8}$) derivatives have been prepared by a repetitive formylation-reduction sequence.