Alkylation of 1,4-naphthoquinone with cyclopropyl carboxylic acid in the presence of ammonium peroxodisulphonate and silver nitrate afforded a mixture of 2-cyclopropyl- and 2,3- dicyclopropyl-1,4-naphthoquinones. In reactions directed at the synthesis of 5-deoxyjuglomycins A and B, a substituted cyclopropyl-1,4-naphthoquinone was also obtained