作者:R. Reiner、P. Zeller
DOI:10.1002/hlca.19680510812
日期:1968.10.31
AbstractThe hydroxyalkylation of the penicillin nucleus at C‐6 with benzaldehyde and formaldehyde is reported. 6‐aminopenicillanic acid (6‐APA) (2) was used as starting material. Protection of the functional groups and activation of the C‐6 position were effected by converting 6‐APA successively into the Schiff base 13, the methyl ester 14 and the copper complex 15. The latter gave with benzaldehyde the C‐6 monosubstituted complex 17, and with formaldehyde the disubstituted complex 18. The direct α‐hydroxybenzylation of 6‐APA at C‐6 was also carried out with an excess of benzaldehyde at pH 7,5 leading to the SCHIFF base 19. Mild hydrolysis of 19 gave 6‐amino‐6‐(α‐hydroxybenzyl)‐penicillanic acid (21). Phenylacetylation of the latter yielded the penicillin G analogue 22. Direct reaction of 6‐APA with formaldehyde took place only in the presence of salicylaldehyde, giving the oxazolidine 24, from which the amino acid 25 could not be obtained. The new compounds showed only weak antibacterial activity as compared with penicillin G.