Abstract Jatrophane diterpenes are structurally intriguing natural products with promising biological properties. Herein, the synthesis of the western fragment of the Euphorbiaceae constituent Pl-3 starting from (1R, 5S)-bicyclo [3.2. 0] hept-2-en-6-one is described. Key steps in the sequence include a Baeyer–Villiger oxidation, an iodolactonization reaction, and the installation of the northern side chain through the addition of a lithiated vinyl ...