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One-carbon homologation of geranyl and farnesyl chlorides to secondary JV-methylamines (12 and 17) via -lithioformamidine alkylations followed by N-alkylation with bromoacetate esters afforded a-(homogeranylamino)and a-(homofarnesylamino)acetates 13 and 18. After -famesylation of 13, hydride reductions gave branched and straight-chain tertiary /3-amino alcohols 15 and 19. The diphosphate derivatives (7 and 8) of 15 and 19 prepared by Sn2 displacements may be regarded as "aza analogs" of plausible carbocation intermediates (5 and 6) in the biosynthesis of squalene and geranylgeranyl diphosphate since, in preliminary collaborative evaluations, they inhibit the respective synthase enzymes at micromolar concentrations.Farnesyl diphosphate (FPP, 1) is situated at an important branch point in the isoprenoid biosynthetic pathway (Scheme I).1-2 3Reductive head-to-head coupling of two molecules of FPP via presqualene diphosphate (2) leads to squalene (3), the precursor of triterpenes and sterols. Chain elongation by alkylation of FPP with isopentenyl diphosphate (IPP) produces geranylgeranyl diphosphate (GGPP, 4), which is an intermediate in the biosynthesis of cyclic diterpenes, carotenoids, dolichol, ubiquinones, phytyl derivatives, and the recently discov-compounds 7,8,14a, 23, and 24 (7 pages). Ordering information is given on any current masthead page.

Β-Bergamotenoic acid, a compound previously shown to stimulate oviposition inH. zea, was converted into a set of bicyclic analogs and tested with a set of acyclic side chain analogs to ascertain the molecular structure that maximizes insect behavioral response. While changes in the bicyclic ring elicited no variation in response, alteration in the side chain structure ofΒ-bergamotenoic acid resulted in significant changes in moth preference. Free rotation about the C-C bond proximal to the carboxylic acid group appears to be an important structural factor, since saturation of the side chain double bond significantly increased activity. The carboxylic acid group seems to be required for strong oviposition stimulation, since analogs lacking the carboxylic acid group exhibited no significant oviposition activity. Oviposition preference ofH. zea was also influenced by the length of the hydrocarbon chain to which the carboxylic acid is attached. While hexanoic acid was found inactive, the ovipositional preference for the heptanoic and octanoic acids was greatest for the one 8-carbon tested. This and other work suggest that carboxylic acids of specific chain lengths influence the oviposition behavior of bothHelicoverpa andHeliothis species and may be associated with host-plant selection. The potential use of this information in designing integrated pest management strategies for control ofH. zea is discussed.