AbstractThis paper describes the total synthesis ofcis‐shisool through intermediate 3, which was derived from the Diels‐Alder adduct 4 (or 5). The structure of the isomers produced by the Diels‐Alder reaction of cyclohexadiene and crotonate has been elucidated by means of GC and NMR. Methylenation of 12 with Zn‐CH2Br2‐TiCl4or Ph3P=CH2retains the stereochemistry of the carbon atom adjacent to the carbo