Methyl 4-(4-fluorobenzylidene)-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate → Methyl 4-(4-fluorobenzyl)-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate

Participants

Reaction Steps

The title compound was synthesized from tosyl protected methyl 4-oxo-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate (methyl 4-oxo-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate) (0.60 g, 1.8 mmol) and 4-fluorobenzylmagnesium chloride (0.25M in THF, 52 mL, 13 mmol) according to General Procedure 3 to give exo olefin-containing methyl 4-(4-fluorobenzylidene)-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate (as a mixture of cis/trans isomers), then hydrogenation according to General Procedure 6. In this example, Degussa type, 5% palladium on carbon (˜0.200 g, 0.2 mmol) was used, and the reaction placed under a hydrogen atmosphere in a Parr shaker (˜40 PSI) for 2 hours. Purification by column chromatography (Isco CombiFlash) eluting with a gradient of 0-50% EtOAc/heptane affording the title compound as white crystals: 0.070 g (14% yield). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.05-2.15 (m, 1H), 2.44 (s, 3H), 2.55-2.65 (m, 1H), 2.70-2.85 (m, 2H), 3.08 (t, 1H), 3.20-3.35 (m, 1H), 3.71 (s, 3H), 6.49 (s, 1H), 6.95-7.00 (m, 2H), 7.10-7.15 (m, 1H), 7.30-7.35 (d, J=8.4 Hz, 2H), 7.87 (d, J=8.4 Hz, 1H).

Provenance & Evidence