Kanegafuchi Kagaku Kogyo Kabushiki Kaisha

Isao Sada

Kiyoshi Watanabe

Noboru Ueyama

Kazunori Kan

Takehisa Ohashi

Akimasa Miyama

Shingo Matsumoto

Takeisa Ohashi

The present invention relates to .beta.-lactam compound having the formula (I): ##STR1## wherein R.sup.1 is a trialkylsilyl group, dimethyl-1,1,2-trimethylpropylsilyl group, acetyl group, benzyloxycarbonyl group, O-nitrobenzyloxycarbonyl group, p-nitrobenzyloxycarbonyl group or t-butyl group, R.sup.2, R.sup.3 and R.sup.4 are a member selected from the group consisting of a lower alkyl group having 1 to 6 carbon atoms, phenyl group and an aralkyl group and a process for preparing the compound which comprises reacting enolsilylethers having the formula (III): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as above, with chlorosulfonylisocyanate and then reducing the obtained product. The .beta.-lactam compound of the present invention is a useful intermediate for preparing carbapenem .beta.-lactam compound.

Enolsilyl ether compound

A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reactig a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as difined above and R.sup.2, R.sup.3 and R.sup.4 are the same or different and each is a lower alkyl group having 1 to 4 carbon atoms or an aralkyl group, with acetic anhydride in the presence of a base and a catalyst selected from the group consisting of an organic strong acid, a mineral acid, a Lewis acid, a halogenated acyl compound having the formula (IV):

Process for preparing 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives

A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reacting a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as defined above, and R.sup.2, R.sup.3 and R.sup.4 are a lower alkyl group having 1 to 6 carbon atoms, phenyl group or an aralkyl group, with acetic anhydride in an organic solvent in the presence of a low concentration of a substituted pyridine. According to the present invention, there can be obtained 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives, which are useful intermediates for preparing carbapenem .beta.-lactam antibiotics.

A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): ##STR1## wherein R.sup.1 is a protective group for the hydroxyl group, which comprises reacting a .beta.-lactam compound having the formula (I): ##STR2## wherein R.sup.1 is as defined above, R.sup.2, R.sup.3 and R.sup.4 are a lower alkyl group having 1 to 6 carbon atoms, phenyl group or an aralkyl group and R is a protective group for N, with acetic anhydride in an organic solvent in the presence of a base, and removing the protective group for N. 4-Acetoxy-3-hydroxyethylazetidin-2-one derivatives are useful intermediates for preparing carbapenem .beta.-lactam antibiotics such as thienamycin and penem .alpha.-lactam antibiotics.

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Akashi, Japan

Isao Sada