Abstract By a simple process, 3-methoxyjuglone (= 8-hydroxy-2-methoxy-1, 4- naphthoquinone; 9) has been synthesized from 1, 2, 4-trimethoxybenzene (5) and converted, after prenylation, to α-caryopterone (1; Scheme 1), a pyranojuglone pigment from Caryopteris clandonensis. On the other hand, juglone (= 5-hydroxy-1, 4-naphthoquinone; 12) was regioselectively prenylated at C (2) via its 1-methoxy-cyclohexa-1, 3-diene adduct ...
