Preparation of chlorofluoroacetic acid derivatives for the analysis of chiral alcohols

(R)- and (S)- Chlorofluoroacetic acid (CFA) esters of several chiral secondary alcohols have been prepared and compared with the corresponding esters of Mosher's acid. CFA itself is a readily accessible and optically stable acid which gives the expected diastereoisomeric products with chiral alcohols without epimerization. The resulting diastereoisomers are more volatile than those derived from Mosher's acid, and are well resolved by both GC and HPLC. Both H-1 and F-19 NMR spectra of CFA esters show characteristic signals in regions rarely overlapped by other signals. Since CFA is a strong organic acid, it reacts with alcohols spontaneously to give esters without any additional catalysis

New mimics of the acetate function in pheromone-based attraction

Several analogues of (Z)-8-dodecenyl acetate (la), the major pheromone component of the Oriental fruit moth, Cydia molesta, with chloroformate and lactone functional groups in place of the acetate moiety, were synthesized and investigated for their biological activity at four evaluation levels, i.e. by electroantennography (EAG), electrosensillography (ESG), short-range sexual stimulation and activation in the flight-tunnel. We found very strict requirements on the shape as well as on the electron distribution of the acetate group for a productive interaction with the receptor. The behavioral results showed that, among the analogues investigated, the chloroformate lb, alken-4-olide 2a and also dodecyl acetate (lc) possess significant (60-85%) inhibitory activities. Based on electrophysiological evidence demonstrating that (i) only lb is competing with the major pheromone component la for the same receptor sites on the male antennal sensilla, (ii) lc elicits moderate EAG but no ESG responses and (iii) 2a does not produce any electrophysiologicai response at all, three possible inhibitory mechanisms by which these analogues are acting could be distinguished

Behavioral observations and measurements of aerial pheromone in a mating disruption trial against pea moth Cydia nigricana F (Lepidoptera, Tortricidae)

Synthetic sex pheromone of the pea moth Cydia nigricana, (E,E)-8,10-dodecadien-1-yl acetate (E8,E10-12:Ac), was applied in a 3-ha pea field at a rate of 17 g/ha, in two different dispenser formulations. Aerial concentrations within pea canopy, as determined by a field electroantennogram (EAG) apparatus, were 2 and 3 ng/m(3) in the two dispenser treatments. The validity of the EAG measurements was corroborated by sampling of field air, followed by gas chromatographic quantification of E8,E10-12:Ac. Males were attracted to fresh dispensers releasing E8,E10-12:Ac plus less than 2% of the antagonistic E, Z; Z, E; and Z, Z isomers. Two days after placement, the proportion of these isomers had increased to 6%. Males were then no longer attracted to the dispensers, but were observed to fly out of the treated field. Male attraction to calling females was almost entirely suppressed, and attraction to traps baited with synthetic pheromone was significantly reduced. Larval infestation in the pheromone-treated field was 2%, compared to 36% in a control field