Several insect sex pheromone components and structural analogues have been characterized by 13C NMR spectroscopy. The evaluation of the difference between the chemical shift values of the allytic carbons present in the diunsaturated pheromone components and those of the carbons having the same position on the n-alkane chain of the corresponding saturaated compounds was used to assign the configuration of the CC double bonds present into such dienic compounds. The technique avoids the need to use the nuclear Overhausser effect; it allows quantitative evaluation, with good accuracy, of the stereoisomeric composition of mixtures of synthetic monoenic or dienic pheromone components such as (Z)- and (E)-9-tetraceden-1-yl acetate and (Z)- and (E)-9,11-dodecadien-1-yl acetate.
Insect pheromone components. Use of carbon-13 NMR spectroscopy for assigning the configuration of carbon-carbon double bonds of monoenic or dienic pheromone components and for quantitative determination of Z/E mixtures
ROSSI, RENZO;CARPITA, ADRIANO;VERACINI, CARLO ALBERTO
1982-01-01
Abstract
Several insect sex pheromone components and structural analogues have been characterized by 13C NMR spectroscopy. The evaluation of the difference between the chemical shift values of the allytic carbons present in the diunsaturated pheromone components and those of the carbons having the same position on the n-alkane chain of the corresponding saturaated compounds was used to assign the configuration of the CC double bonds present into such dienic compounds. The technique avoids the need to use the nuclear Overhausser effect; it allows quantitative evaluation, with good accuracy, of the stereoisomeric composition of mixtures of synthetic monoenic or dienic pheromone components such as (Z)- and (E)-9-tetraceden-1-yl acetate and (Z)- and (E)-9,11-dodecadien-1-yl acetate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.