3-{[((3S,10S,30S,12R,19R)-2-Ethyl-30-hydroxy-27-(hydroxyimino)-3,19,28-trimethyl-9,13,25-trioxa-8-oxospiro[2H-3,4,5,6-tetrahydropyran-6,6'-tetracyclo[15.6.1.1<4,8