Triphenylphosphine → (R)-3-(5-Cyano-2-oxo-2H-pyridin-1-yl)-pyrrolidine-1-carboxylic acid 5-hydroxy-adamantan-2-yl ester

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Reaction Steps

Diethyl azodicarboxylate (40% in toluene, 1.7 mL) is added to a mixture of (S)-3-hydroxy-pyrrolidine-1-carboxylic acid 5-hydroxy-adamantan-2-yl ester (ca. 1:1 mixture of cis- and trans-isomer, 0.50 g), 6-oxo-1,6-dihydro-pyridine-3-carbonitrile (0.22 g), triphenylphosphine (0.97 g), and tetrahydrofuran (10 ml) at room temperature. The resulting mixture is stirred for 2 h and then concentrated. The residue is chromatographed on silica gel (ethyl acetate/methanol 95:5→80:20) and then on reversed phase (HPLC, acetonitrile/water containing 1.36% trifluoroacetic acid) to give the title compound as a mixture of two diastereomers (cis/trans ca. 1:1). Yield: 8 mg (1% of theory); LC (method 1): tR=1.03/1.06 min; Mass spectrum (ESI+): m/z=384 [M+H]+.

Provenance & Evidence