(+)-4,5-dihydro-1-[[[(2,2-dimethyl-1-oxopropoxy)methoxy](4-phenylbutyl)phosphinyl]acetyl]-3-phenyl-1H-pyrazole-5-carboxylic acid, phenylmethyl ester → (+)-4,5-dihydro-1-[[[(2,2-dimethyl-1-oxopropoxy)methoxy] (4-phenylbutyl)phosphinyl]acetyl]-3-phenyl-1H-pyrazole-5-carboxylic acid

Participants

Reaction Steps

The diester product from part (d) (2.0 g.) is dissolved in 50 ml. of methanol containing 0.5 g. of 5% palladium on carbon catalyst and hydrogenated at 50 psi on a Parr apparatus until cessation of hydrogen uptake (2-4 hours). The catalyst is filtered off and the filtrate is concentrated in vacuo. The residue is triturated with acetonitrile or purified by flash chromatography to give (+)-4,5-dihydro-1-[[[(2,2-dimethyl-1-oxopropoxy)methoxy] (4-phenylbutyl)phosphinyl]acetyl]-3-phenyl-1H-pyrazole-5-carboxylic acid.

Provenance & Evidence