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 15(Scheme
通过一个简单的方法,由
1,2,4-三甲氧基苯(5)合成了3-甲氧基juglone(= 8-羟基-
2-甲氧基-1,4-萘醌; 9),并在
异戊二烯化后转化为α-
环戊烯酮(1;方案1),来自Caryopteris clandonensis的
吡喃juglone
颜料。另一方面,通过其1-甲氧基-环己-1,3-二烯加合物15 (方案2),在C(2)上对juglone(= 5-hydroxy-1,4-naphthoquinone; 12)进行区域选择性炔丙基化。如此形成的2-异
戊烯基胡克隆酮(4)在氧化和其他反应后导致1。