5a,5b,8,8,11a-pentamethyl-9-(oxan-2-yloxy)-1-prop-1-en-2-yl-1,2,3,4,5,6,7,7a,9,10,11,11b,12,13,13a,13b-hexadecahydrocyclopenta[a]chrysene-3a-carbaldehyde