| abstract |
ABSTRACT OF THE DISCLOSURE Process for preparing esters of (5R, 6S)-carba-moyloxymethyl-6-[1 (R)-hydroxyethyl]-2-penem-3-carboxylic acid, useful as orally adsorbed antibiotics. The esters have the general formula II in which R represents an acetoxymethyl, pivaloyloxymethyl, methoxymethyl, methoxy-ethoxymethyl, phthalidyl, .alpha.-ethoxycarbonyloxyethyl, acetamidomethyl or benzamidomethyl group. II The process is characterized by esterifying in appropriate conditions a compound of formula III III with RX, wherein R is as above defined and X is a common leaving group. |