| 摘要 |
Avermectin analogs are disclosed wherein the 6,6-spiroketal ring system has been reduced in size to a 6,5-spiroketal ring system by the deletion of the 25-position carbon atom and the 25-alkyl substituent and which has a 23-acyl cycloalkyl, phenyl or substituted hydroxymethyl substituent. This is accomplished by opening the outer spiroketal ring with the elimination of ring carbon atoms 23, 24 and 25 and the alkyl substituent at the 25-position and incorporation a new component, reclosing the spiroketal to a 5-membered ring with a 23-acyl substituent and new substituents at the 24-position. The compounds are used as anti-parasitic insecticidal and anti-helmintic agents in humans and animals and compositions containing such compounds as the active ingredient thereof are also disclosed. |
