“…(3 S ,4 S )-{ O -[(4-Hydroxy-3-{(1 S ,2 R ,4 R )-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl}-5-{(1 R ,2 S ,4 S )-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl}phenyl)methyl]}-4,8,13,18-tetramethyl-20-oxo-9-ethenyl-14-ethylphorbin-3-propanoate ( 8 ) was obtained according to [ 15 ].…”