Spectinomycin modification. V. The synthesis and biological activity of spectinomycin analogs with ring-expanded...

Tiffeneau-Demjanov rearrangement of 3'-(R)-N,N'-dibenzyloxycarbonyl-3'-aminomethyl-dihydrospectinom ycin results in ring expansion affording the homologous analog with a seven-membered sugar ring. In stark contrast, attempted rearrangement of the 3'-S-isomer leads only to epoxide formation. Deprotection of the ring-expanded homolog gives homospectinomycin. The synthesis and biological activity of this interesting new member of the spectinomycin series and the derived dihydrohomospectinomycin is detailed in this paper.