APPROACHES TO CARBOCYCLIC ANALOGS OF THE POTENT NEURAMINIDASE INHIBITOR 4-GUANIDINO-NEU5AC2EN - X-RAY MOLECULAR-STRUCTURE OF -BENZYLOXYMETHYL-4-FORMYLCYCLOHEX-3-ENYL]ACETAMIDE

Various approaches using Diels-Alder chemistry have been established f or the synthesis of truncated carbo cyclic analogues 4 and 6 of 4-guan idino-Neu5Ac2en. In the case of compound 4, elaboration of an initial adduct from Danishefsky's diene and the dienophile 7 allowed access to the key enone 26. Methylenation of the carbonyl group and azide-induc ed opening of an intermediate oxazoline established the required frame work regio- and stereo-specifically. Compounds 4 and 6 were found to r etain interesting levels of antiviral activity comparable to those sho wn by their oxygen-containing counterparts.