A Chemical Study of Burley Tobacco Flavour (Nicotiana tabacum L .) V. Identification and Synthesis of the Novel Terpenoid Alkaloids 1, 3, 6, 6‐Tetramethyl‐5, 6, 7, 8‐tetrahydro‐isoquinolin‐8‐one and 3, 6, 6‐Trimethyl‐5,6‐dihydro‐7H‐2‐pyrindin‐7‐one

GLC. allowed the isolation of 1, 3, 6, 6‐tetramethyl‐5, 6, 7, 8‐tetrahydro‐isoquinolin‐8‐one (A) and 3,6,6‐trimethyl‐5,6‐dihydro‐7H‐2‐pyrindin‐7‐one (D) from Burley tobacco condensate (about 0.1% each). The structures and syntheses of these novel terpenoid alkaloids are described, and a possible way for their formation in tobacco is suggested.