The isomerization of caryophyllene oxide, one of the most widespread sesquiterpenes found in various essential oils, is catalyzed by the acidic Cs salt of tungstophosphoric heteropoly acid, Cs_2.5H_0.5PW₁₂O₄₀, to give rare polycyclic oxygenated sesquiterpenes with a clovane structure. Cloven-9-ol and clovan-2,9-diol can be obtained with up to 80% combined selectivity and 60% individual selectivity each (under different reaction conditions), which is the best result reported for these compounds so far. The process is environmentally benign and can be performed not only in conventional solvents such as 1,2-dichloroethane and acetone but also in eco-friendly “green” organic solvents such as dimethylcarbonate, diethylcarbonate and 2-methyltetrahydrofuran. The reactions occur under ambient conditions at low catalyst loadings without catalyst leaching. The solid catalyst can be simply centrifuged from the reaction mixture, and low boiling solvents can be separated from reaction products by distillation.

钨酸磷杂多酸的酸性Cs盐催化Cs _2.5 H _0.5 PW ₁₂ O ₄₀催化氧化石竹烯，这是在各种精油中最广泛使用的倍半萜烯之一。，得到具有氯仿结构的稀有多环含氧倍半萜。可以以高达80％的组合选择性和60％的个体选择性（在不同的反应条件下）获得Cloven-9-ol和clovan-2,9-二醇，这是迄今为止报道的这些化合物的最佳结果。该方法对环境无害，不仅可以在常规溶剂（例如1,2-二氯乙烷和丙酮）中进行，而且可以在生态友好的“绿色”有机溶剂（例如碳酸二甲酯，碳酸二乙酯和2-甲基四氢呋喃）中进行。反应在低催化剂负载的环境条件下发生，而没有催化剂浸出。固体催化剂可以简单地从反应混合物中离心分离，低沸点溶剂可以通过蒸馏从反应产物中分离出来。