Thiadiazolines Thiosemicarbazones article 1,3,3 trimethyl 2 norcamphanone Asymmetric spiro-heterocyclic compounds Spiro-nitrogenheterocycles Spiro-sulphur heterocycles Terpenoids Terpenones X ray diffraction acetylation camphor carbohydrate synthesis carbon nuclear magnetic resonance chirality heterocyclic compound menthone proton nuclear magnetic resonance stereochemistry structure analysis terpene derivative thiadiazoline derivative thiosemicarbazone derivative unclassified drug n [aza(1,7,7 trimethylbicyclo[2.2.1]hept 2 ylidene)methyl]acetamide 1 tetralone derivative Antiviral Arenavirus Haemorrhagic fever Junin virus