(7S,11S,13S,17S,12R,14R,15R,16R,18R)-2,15,17-Trihydroxy-18-(hydroxymethyl)-11-methoxy-3,7,12,14,16,22-hexamethyl-34-(2-methylpropyl)-6,23,32-trioxo-8,33-dioxa-24,27,29-triazaspiro[pentacyclo[23.6.1.1<4,7