1,3-Dibromopropane → ethyl 3,4-dihydro-2H-pyrano[2,3-b]indolizine-10-carboxylate

Participants

Reaction Steps

A solution of 1,2-di-[(ethoxycarbonyl)methyl]pyridinium bromide (1.5 g, 0.0045 mole) and 1,3-dibromopropane (0.45 ml, 0.0045 mole) in ethanol (10 ml) was added over 5 minutes to a stirred solution of potassium hydroxide (0.75 g, 0.0134 mole) in ethanol (15 ml) at 5° C. The mixture was then allowed to warm upto room temperature and stir for 20 h. The reaction mixture was diluted with water (150 ml) and extracted with ethyl acetate (2×100 ml). The combined extracts were dried (Na2SO4) and concentrated in vacuo to leave a brown oil. This was chromatographed on silica gel eluting with ether to afford the title compound as a yellow oil.

Provenance & Evidence