(2R,5S)-9-[(3R)-3,7-dimethylocta-1,6-dien-3-yl]-5-(hydroxymethyl)-1-methyl-2-(propan-2-yl)-1,2,4,5,6,8-hexahydro-3H-[1,4]diazonino[7,6,5-cd]indol-3-one