Ammonium Chloride → Methyl (1aRS,7bSR)-5-(2,2-dimethylpropionylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Participants

Reaction Steps

Methyl (1aRS,7bSR)-1,1-dibromo-5-(2,2-dimethylpropionylamino)-1,1a,2,7b-tetrahydro-cyclopropa[c]chromene-4-carboxylate (Intermediate 44, 1.13 g) was suspended in ethanol (30 mL). Zinc dust (1.17 g), followed by ammonium chloride (1.31 g) were added and the reaction mixture was heated to reflux, under an atmosphere of nitrogen, for 6 hours. After cooling, the solid was filtered off and washed with ethyl acetate. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ether and cyclohexane, with a gradient of 5-12.5% to give methyl (1aRS,7bSR)-5-(2,2-dimethylpropionylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.310 g) as a colourless oil.

Provenance & Evidence