A series of five 12-dodecanolides have been synthesised containing CF 2 groups at C5, C6, C7, C8 and in one case, a double substitution at C5 & C8, as a strategy to bias the conformational space accessed by these macrocycles, and to assess if the analogues may act as mimetics of 13-membered macrolide pheromones associated with the emerald ash borer. Accordingly individual syntheses of 5,5-difluoro- 5 , 6,6-difluoro- 6 , 7,7-difluoro- 7 , 8,8-difluoro- 8 and 5,5,8,8-tetrafluoro- 9 , 12-dodecanolides are outlined, and X-ray structural data were obtained for three (5 , 8 and 9) of these compounds. The structures show clearly that the CF 2 groups occupy 'corner' locations in the macrocycle consistent with their ability to bias accessible conformations. The fluorine containing 12-dodecanolides all generated an electro-antennogram response in female beetles. Image 1 [ABSTRACT FROM AUTHOR]