A new process involving novel intermediates for the synthesis of antibiotics comprises:
1. acylation of a dianion followed by reduction to introduce an arylhydroxymethyl or alkylhydroxymethyl group; alternatively, alkylation followed by oxidation and reduction to introduce the same group;
2. oxidative decarboxylation to introduce a 4-acetoxy group;
3. silyl enolether chemistry on the acetoxy intermediate using Lewis acids to introduce the side chain, or replacement of the acetoxy group with a triphenylmethylthio group; and
4. ring closures.
Process for preparing 4-acetoxy-3-hydroxyethylazetizin-2-one derivatives
申请人:KANEGAFUCHI KAGAKU KOGYO KABUSHIKI KAISHA
公开号:EP0167154A1
公开(公告)日:1986-01-08
A process for preparing 4-acetoxy-3-hydroxyethyl- azetizin-2-one derivative having the general formula (II):
wherein R' is a protective group for hydroxy group, which comprises reacting the β-lactam compound having the general formula (I):
wherein R' is above, R2, R3 and R4 are a lower alkyl group of C, to C4, phenyl group or aralkyl group and R is a protective group for N, with acetic anhydride in the organic solvent in the presence of base and then removing the protective group for N. 4-Acetoxy-3-hydroxyethylazetizin-2-one derivatives are the useful intermediates for preparing carbapenem β-lactam antibiotics such as thienamycin and penem β-lactam antibiotics.
The present invention relates to β-lactam compound having the general formula (I):
wherein R1 is a protective group for hydroxy group, R2, R3 and R4 are selected from a lower alkyl group of C, to C4, phenyl group and aralkyl group and a process for preparing thereof which comprises reacting enolsilylether having the general forumal (III)
wherein R1, R2, R3 and R4 are as above, with chlorosulfonylisocyanate and then reducing the obtained product. β-Lactam compound of the present invention is a useful intermediate for preparing carbapenem β-lactam compound.
Beta-lactam compound and process for preparing the same
申请人:KANEGAFUCHI KAGAKU KOGYO KABUSHIKI KAISHA
公开号:EP0230248A1
公开(公告)日:1987-07-29
A β-lactam compound having the formula (I):
wherein R¹, R² and R³ are a member selected from the group consisting of a lower alkyl group having l to 6 carbon atoms, phenyl group and an aralkyl group, a process for preparing the same, which comprises reacting an enolsilylether having the formula (II):
wherein R¹, R² and R³ are as defined above, with chlorosulfonylisocyanate and then reducing the obtained product. The β-lactam compound of the present invention is a useful intermediate for preparing carbapenem β-lactam compound.
Process for preparing 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives
申请人:KANEGAFUCHI KAGAKU KOGYO KABUSHIKI KAISHA
公开号:EP0247378A1
公开(公告)日:1987-12-02
A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II):
wherein R¹ is a protective group for the hydroxyl group, which comprises reacting a ß-lactam compound having the formula (I):
wherein R¹ is as defined above, and R², R³ and R⁴ are a lower alkyl group having l 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 ß-lactam antibiotics.