In addition, the indole Main is substituted at R3 with a carbonyl group which can be also bonded to the napthalene moeity. Napthalene is really a bicyclic construction of two fused benzene rings. This carbonyl bridge of JWH-018 classifies it like a ketone. JWH-018 is undoubtedly an analog of THJ-018, https://spice-gold55285.bloggosite.com/39760283/indicators-on-5f-pb-22-you-should-know