The reactions of 2 (3,5 dimethylpiperidino)benzaldehyde with Meldrum´s acid and cyclo hexane 1,3 dione occur as a tandem of the Knoevenagel condensation and cyclization pro moted by the tert amino effect. The cyclization yields only one isomer with the axial hydrogen atoms in positions 4 and 4a of the benzoquinolizine ring.

Fused pyridine derivatives R 0450Stereoselective Synthesis of Spiro Derivatives of 2,4-Dimethyl-2,3,4,4a,5,6-hexahydro-6H-benzo[c]quinolizine. -The reaction of benzaldehyde derivative (I) with Meldrum's acid and cyclohexane-1,3-dione occurs as tandem of the Knoevenagel condensation and cyclization promoted by the tert-amino effect to afford only one isomer of spiro compounds (III) with axial hydrogen atoms in position 4 and 4a of the benzoquinolizine ring. -(DEEVA, E. V.; GLUKHAREVA, T. V.; ZYBINA, N. A.; MORZHERIN*, Y. Y.; Russ. Chem. Bull. 54 (2005) 6, 1537-1538; Ural State Tech. Univ., Ekaterinburg 620002, Russia; Eng.) -M. Kowall 29-143