| 摘要 |
<p>There are disclosed novel avermectin derivatives wherein the 3 sec - or 3 min -methoxy group and/or the 4 sec - or 4 min -hydroxyl group are replaced by hydrogen. The 3 sec - or 3 min -desmethoxy-avermectins can further be derivatized at the 4 sec - or 4 min -positions as the amino, semicarbazone or oxime analogs. The 3 sec - or 3 min -desmethoxy-avermectins are prepared by the reaction of Samarium iodide on the corresponding 4 sec - or 4 min -oxo-avermectins. The 4 sec -or 4 min -deoxo-avermectins are prepared by radical deoxygenation of the corresponding hydroxy-avermectins. Di-deoxygenated avermectin derivatives are obtained by combination of these two methods or by treating avermectin aglycone or avermectin monosaccharide with a dihydropyran. The new compounds are potent anti-parasitic agents, in particular, the compounds are anthelmintic, insecticidal and acaridical agents.</p> |
