tert-butyl 1H-pyrrole-1-carboxylate → 2-Acetyl-3-methyl-8-(tert-butoxycarbonyl)-8-azabicyclo[3.2.1]octa-2,6-diene

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Reaction Steps

A solution of 3-diazo-4-methylpent-4-ene-2-one (2.30 g, 18.5 mmol) in hexane (25 ml) was added over 3 hours by means of a syringe pump to a stirred solution of N-tert-butoxycarbonyl pyrrole (9.18 g, 55 mmol) and rhodium(II) octanoate (0.07 g, 0.09 mmol) in refluxing hexane (10 ml) under an argon atmosphere. The mixture was refluxed for a further 1 hour period, and solvent was then removed using a rotary evaporator under reduced pressure. Purification of the product by silica gel column chromatography (using 2 parts diethyl ether and 8 parts petroleum ether, and 4 parts diethyl ether and 6 parts petroleum ether) yielded 2-acetyl-3-methyl-8-(tert-butoxycarbonyl)-8-azabicyclo[3.2.1]octa-2,6-diene, which is an orange liquid.

Provenance & Evidence