Hyperolid reed frogs are one of the few families of Anurans known to possess glands that emit volatile compounds used in chemical communication. Hyperolius cinnamomeoventris, a model species, possesses a gular gland on its vocal sac that emits chemicals, and sends visual and auditory signals during calling. Previous investigations have shown that the glandular compounds are typically macrocyclic lactones. However, in this work, we show that another major constituent of the male specific gland is (10R,1S,6R,7R,10R)-amorph-4-ene-10β-ol [(1R,4R,4aR,8aS)-4-isopropyl-1,6-dimethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1-ol]. This compound was synthesized for the first time and has the opposite configuration to amorph-4-ene-10β-ol known from plants. A short synthesis using an organocatalytic approach through a tandem Mannich/intramolecular Diels–Alder reaction led to a mixture of cadinols, which was used for the assignment of the natural cadinol structures and their stereoisomers.
苇蛙(Hyperolid reed frogs)是已知的少数几个拥有腺体的无尾目动物家族之一,这些腺体能释放出用于化学交流的挥发性化合物。模式物种 Hyperolius cinnamomeoventris 的声囊上有一个腺体,能释放化学物质,并在鸣叫时发出视觉和听觉信号。以前的研究表明,腺体化合物通常是大环内酯。然而,在这项工作中,我们发现雄性特异性腺体的另一种主要成分是(10R,1S,6R,7R,10R)-吗啉-4-烯-10β-醇[(1R,4R,4aR,8aS)-4-异丙基-1,6-二甲基-1,2,3,4,4a,7,8,8a-八氢萘-1-醇]。该化合物是首次合成,其构型与植物中已知的非晶-4-烯-10β-醇相反。通过串联曼尼希/分子内 Diels-Alder 反应,使用有机催化方法进行简短合成,得到了一种卡丁醇混合物,并用于确定天然卡丁醇结构及其立体异构体。