| Insect attractants or pheromones provide a sustainable and reliable method in Integrated Pest Management. This work revolves around the synthesis of two such insect attractants. Ceralure B1 and (3Z,5E)-3,5-tetradecadienyl acetate are the attractants of the medfly, Ceratitis capitata and the carpenterworm moth, Prionoxystus robiniae respectively. The Mediterranean fruit fly or the medfly is a serious pest of innumerable fruits and crops spread worldwide. On the other hand the carpenterworm moth is indigenous to the Northern Americas and is a live woodborer causing substantial damage to lumber. The route envisaged towards the synthesis of ethyl (1 R,2R,5R)-5-iodo-2-methylcyclohexane-1-carboxylate or Ceralure B1 was based upon the Birch reduction of 5-methoxy-2-methylbenzoic acid (5). The first step was conversion of the acid (5 ) via the Birch reduction to a lactone, (1S,2 S,5S)-2-methyl-6-oxabicyclo[3.2.1]octan-7-one ( 2), which could then be converted to Ceralure B1 as per methods described in literature. However, the route proposed ended up giving the (1 S*,2R*,5S*)-lactone (2a) rather than (1S,2S,5 S)-lactone (2) required to get to Ceralure B1. The route towards the synthesis of 3Z,5E-tetradecadienyl acetate was based upon the ring opening of a 2-alkylated pyridine by Hoffman degradation, which selectively gives Z,E-stereochemistry. The ring opening satisfactorily gave the diene with the required Z,E-stereochemistry. However, the diene was unstable and decomposed readily. The methods and chemistry employed to get to these two attractants by the strategies mentioned above has been described herein. |
