Abstract 7-Hydroxy-2, 3-dihydro-1H-indolizin-5-ones with various substituents as well as their pyranno annelated derivatives were synthesized by reaction of Δ 1-pyrrolines with 'magic malonates'(activated malonates). The evaluation of these compounds on Mycobacterium tuberculosis H37Ra, Escherichia coli B and Staphylococcus aureus ATCC 25923, shows significant inhibitory effects on M. tuberculosis (3b and 3f, MIC= 16 μg/ml). A ...