Abstract A number of ecdysone analogues were prepared to study the effect of structural changes on biological activity. It was found that analogues with the 5α-configuration or a 3, 5- cyclo structure were inactive, that a 3β-hydroxy group enhances activity but is not essential for activity, and that 3β-substituents decrease activity as follows: OMe (60%), OAc (25%) and OEt (10%). The keto diol (3), keto alcohol (9) and amide (36) were found to be highly toxic ...
![10,13-dimethyl-17-(6-methylheptan-2-yl)-1,2,4,5,6,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one Structure](https://image.chemsrc.com/caspic/296/29374-80-9.png)