Chemical Modification of the Insecticidal Briantheins X and Y

Manipulation of the allylic chloride functionality in briantheins X and Y provided 10 new analogues of these gorgonian diterpenes as part of a continuing study of structure−activity relationships in this family of insecticidal compounds. Modified Finkelstein reaction conditions led not only to halogen substitution products but also to rearrangement, dehydrohalogenation, and dehydration products. None of the new compounds showed superior insecticidal activity to brianthein X or Y, although most did result in lower weight gains versus controls.