Abstract: | Kamebanin, alternatively called rel‐(?)‐(1R,4R,8S,9R,10S,13S,16R)‐2,8,16‐trihydroxy‐5,5,9‐trimethyl‐14‐methylenetetracyclo11.2.1.01,10.04,9]hexadecan‐15‐one, C20H30O4, is a natural diterpenoid which has cytotoxic and antibacterial activity. The molecule is composed of three six‐membered rings, which all adopt chair conformations, and one five‐membered ring, which adopts an envelope conformation. The conjugated α‐methylenecyclopentanone ring is the active part in the molecule due to the ring strain. All three hydroxy groups serve as hydrogen‐bond donors and acceptors, forming a continuous two‐dimensional network. |