(2S,4R,6S,7S)-Methyl 3,3-dimethyl-8-oxo-7-phenoxacetamido-5-p- tolylsulphoryl-4-thia-1,5-diazabicyclo-[4.2.0]octane-2-carboxylate S-p-tolylsulphonylimide was thermolysed in refluxing toluene to afford quantitatively (3S,4S)-1-(1-methoxycarbonyl-2-methylprop-2-enyl)-3- phenoxyacetamido-4-[N-(p-tolylsulphonylaminothio)-p-tolylsulphonylamino] azetidin-2-one, by a ß-elimination mechanism. Treatment of the monocyclicazetidinone with triphenylphosphine afforded methyl N-(a-phenoxyacetamido-ß-p-tolylsulphonylacryloyl)-ß?- didehydrovalinate, which underwent addition of alcohols to the enamine double bond to form gem-alkoxy-amine dipeptides. The reduction of both the monocyclic azetidinone and the enamine dipeptide with sodium borohydride is described.
|Number of pages||4|
|Journal||Journal of the Chemical Society, Perkin Transactions 1|
|Publication status||Published - 1975|