Scutebata F barbatine C 3-Pyridinecarboxylic acid, (3S,4'aR,5'S,6'R,6'aR,10'R,10'aS,10'bR)-5',6'-bis(acetyloxy)-1',2',4,4'a,5,5',6',6'a,9',10',10'a,10'b-dodecahydro-4'a,6'a,7',10'b-tetramethyl-5-oxospiro[furan-3(2H),3'-[3H]naphtho[2,1-b]pyran]-10'-yl ester