Allyl iodide → 1,2-Pyrrolidinedicarboxylic acid, 2-(2-propen-1-yl)-, 2-methyl 1-(phenylmethyl) ester

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Reaction Steps

N-benzyloxycarbonylproline methyl ester (13 g) in THF (20 ml) was added dropwise to lithium diisopropylamide (27.5 ml, 2M in hexane/THF) in THF (100 ml) at −78° C. under nitrogen. The mixture was stirred for 30 minutes and then allyl iodide (5.5 ml) was added dropwise and the mixture stirred for a further 30 minutes and then allowed to warm to ambient temperature. The mixture was then added to aqueous ammonium chloride (200 ml) and extracted with ether (2×200 ml). The ether layer was evaporated and the residue was purified by chromatography on silica using a gradient of hexane increasing to 20% ethyl acetate:hexane. The appropriate fractions, evaporated to dryness, gave methyl (RS)-2-allyl-N-(benzyloxycarbonyl)prolinate (9 g) as an oil.

Provenance & Evidence