Process for the preparation of 2-thio penem derivatives and intermediates therefor
申请人:BEECHAM GROUP PLC
公开号:EP0046363A1
公开(公告)日:1982-02-24
The present invention provides a process for the preparation of a compound of the formula (IV):
or salt or ester thereof wherein R1 and R2 are independently hydrogen; an organic radical bonded via a carbon atom to the ring carbon atom; a free, etherified or esterified hydroxy or mercapto group; an amino or acylamino group; or together R1 and R2 represent a group = CR5R6 wherein R5 and R6 are the same or different and each represent hydrogen or a hydrocarbon or heterocyclic group optionally substituted with a functional group; and R3 represents an organic radical; which process comprises reacting a compound of the formula (V):
wherein Rx is hydrogen or a blocking group and R4 is an organic radical; with a thiol or reactive derivative thereof. The compounds of the formula (IV) are useful as antibiotics and [β-lactamase inhibitors, as are the compounds of the formula (V). This invention also provides the novel compounds of the formula (V) and certain novel compounds within formula (IV). Their preparation and use are described.
Treatment of 4-acetoxy-2-azetidinone (9) with various sodium alkyl trithiocarbonates gave 4-[(alkylthio) thiocarbonyl] thioazetidinones 10, which were converted into the phosphoranes 8. Intramolecular Wittig reactions of 8 followed by deblocking yielded penem-3-carboxylic acids 5.