Diisopropylethylamine → 1-(2,2-dimethyl-4-oxo-1,3-dioxolan-5-yl)-1-(2-(S)-tert-butoxycarbonylpyrrolidin-1-ylcarbonyl)pentane

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Reaction Steps

To 2-(2,2-dimethyl-4-oxo-1,3-dioxolan-5-yl)hexanoic acid G-1 (10 mmol; prepared as described in Method F, above) in DMF (50 mL) was added proline O-t-butyl ester (10 mmol), DIEA (25 mmol) and PyBOP (10 mmol) and the solution stirred for 8 h. The reaction was diluted with ethyl acetate and washed with water, sodium bicarbonate, brine, and then dried (Na2SO4). The filtrate was concentrated and then purified on silica gel (Merck 60; ethyl acetate/hexane) to afford 1-(2,2-dimethyl-4-oxo-1,3-dioxolan-5-yl)-1-(2-(S)-tert-butoxycarbonylpyrrolidin-1-ylcarbonyl)pentane G-2 (5 mmol, 50%).

Provenance & Evidence