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