Summary:----7'The authentic triterpene lactones 3 and LO_ of the lupane series were obtained by a chemical degradative sequence frn betulinic acid. Canparison of CD spectra of 2 and LQ with those of the lactones 2% and Il_a_ provided additional evidence for their revised formulation.
![(3aS,5aR,5bR,7aR,9S,11aR,11bR,13aS)-9-hydroxy-5a,5b,8,8,11a-pentamethyl-2,3,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-3aH-cyclopenta[a]chrysene-3a-carboxylic acid结构式](https://image.chemsrc.com/caspic/030/756782-76-0.png)
![methyl (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-9-acetyloxy-5a,5b,8,8,11a-pentamethyl-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-carboxylate结构式](https://image.chemsrc.com/caspic/156/4356-30-3.png)