Abstract
Tricyclic compounds (12, 17 and 20) combined with a spiro-system at the 4 position of 1-substituted piperidine were synthesized for pharmacological testing. They could be prepared by a sequence of reactions involving the Pinacol rearrangement of 9-(1-ethoxy-carbonyl-4-piperidinyl) fluorene-9, 4'-diol (9) or the cyclization of 1-benzyl-4-(o-substituted phenyl)-4-carboxy (or cyano) piperidine (15a and 16). 9-(1-Methyl-1, 2, 3, 6-tetrahydro-4-pyridinyl) xanthene (or -anthracene) (21 and 26) and 3-methyl-2, 3, 4, 5-tetrahydro-1H-phenanthro [9, 10-d] azepine (27) were also prepared by the Wagner-Meerwein rearrangement of α hydroxy spiro compounds (19b, 19d, and 11, respectively). Among the compounds synthesized, 1-methyl-1, 2, 3, 5, 6, 7-hexahydrospiro [[4H] azepine-4, 9'-fluorene]-5-ol (8) showed marked anti-convulsant activity.
