Card-20(22)-enolide, 3-- ((O-2,6-dideoxy-4-O-(2-diazo-3-ethoxy-1,3-dioxopropyl)-beta-D-ribo-hexopyranosyl-(1-4)-O-2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1-4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl)oxy)-, (3beta,5beta)-