... Aust. J. Chem., 1996, 49, 1261-1262 Synthetic Routes to 3,9-Dimethylidene- ... A Department of Chemical Engineering, The University of Melbourne, Parkville, Vic. 3052. ... Mass spectrum (ci, NH~+) m/z 120 (11%), 119 (7,8), 118 (loo), 117 (20), 86 (33), 85 (27), 71 (16). ...