Sodium Bicarbonate → (2R,3S,5R,6R) 2-(N-Acetyl)carbamoyloxymethyl-2-methyl-6-phenoxyacetamidopenam-3-carboxylic Acid

Participants

Reaction Steps

A suspension of 10% palladium on charcoal (400 mg) in ethyl acetate (40 ml) and aqueous 0.5% sodium bicarbonate was prehydrogenated and charged with (2R,3S,5R,6R) 2-(N-acetyl)carbamoyloxymethyl-2-methyl-6-phenoxyacetamidopenam-3-carboxylic acid p-nitrobenzyl ester (400 mg 0.68 mmol). The whole was shaken at 50 psi hydrogen pressure for 30 minutes and polish filtered. The aqueous was washed with ethyl acetate (20 ml), combined with a back extract of H2O (20 ml), overlayed with ethyl acetate (25 ml) and adjusted to pH 2.9 with 35% sulfuric acid. The layers were separated and the rich organic phase was washed with water (20 ml), combined with a back extract (EtOAc, 20 ml), dried (4A sieves), polish filtered and concentrated in vacuo to a colorless foam (270 mg) in 87% yield: nmr 100 MHz (CDCl3 --D2O) ppm 7.32 (2, m, m-phenyl H's) 6.96 (3, m, o,p-phenyl H's), 5.59 (2, br s, mag. equiv. C5,C6 --H's), 4.79 (1, s, C3 --H), 4.59 ##STR66## 4.08 (m, AB of C2 --CH2O), 2.25 ##STR67## and 1.58 (3, s, C3 --Me) with small ethyl acetate impurity.

Provenance & Evidence