Synthesis and alkylation of 4-aryl-5-oxo-1h-2,3,4,5-tetrahydroindeno[1,2-b]pyridines*

Reduction of 5-oxo-4-phenyl-1H-4,5-dihydroindeno[1,2-b]pyridines with triethylsilane in trifluoro-acetic acid gave the corresponding 1,2,3,4-tetrahydroindeno[1,2-b]pyridines predominatly with the trans-configured substituents at atoms C(2), C(3), and C(4). Alkylation of the anionic form of the tetrahydroindenopyridines gives the N- and C(4a)-alkyl derivatives.