PREPARATION OF 7-SPIROEPOXY AND 7,7-DISUBSTITUTED CEPHALOSPORANATE 1,1-DIOXIDE FROM 7-DIAZOCEPHALOSPORANATE 1,1-DIOXIDE - REACTIONS OF 7-DIAZOCEPHALOSPORANATE 1,1-DIOXIDE WITH ALDEHYDES

The reactions of tert-butyl 3-acetoxymethyl-3-cephem-7-diazocephalosporanate 1,1-dioxide (I) with acetaldehyde, benzaldehyde, 2-thiophene carboxaldehyde, 3-thiophene carboxaldehyde, 2-furan carboxaldehyde, 3-furan carboxaldehyde and isobutyraldehyde have been studied. Use of boron trifluoride Retherate as a catalyst for these reactions was found to accelerate the reactions markedly and to favour the formation of aldehydes rather than the ketones at C-7 position as the carbonyl product. The products obtained from these reactions and the ratios of carbonyl products to epoxides suggest that the R groups of the carbonyl component have profound influence on the reactions.