(1S,8S,12S,2R,5R,6R,9R)-1-Formyl-5-methyl-10-(methylethyl)-8-[5-benzyl(3,4,5,6,3a,6a-hexahydro-3-oxa-2,5-diazapentalenyl)]tetracyclo[7.4.0.0<2,6