alkaloid fundamental parent tropane CAS:529-17-9 N-methyl-8-azabicyclo[3.2.1]octane chebi_ontology 125.21144 Beilstein:6379695 2,3-dihydro-8-methylnortropidine 1alphaH,5alphaH-tropane tropane C8H15N CHEBI:35615 (1R,5S)-8-methyl-8-azabicyclo[3.2.1]octane InChI=1S/C8H15N/c1-9-7-3-2-4-8(9)6-5-7/h7-8H,2-6H2,1H3/t7-,8+ 125.12045 0 XLRPYZSEQKXZAA-OCAPTIKFSA-N CN1[C@H]2CCC[C@@H]1CC2 tropane alkaloid saturated organic heterobicyclic parent