26906-26-3Relevant articles and documents
Metamorphosis of Castor Oil to Insect Sex-pheromones and Useful Synthons
Ranganathan, S.,Maniktala, Vibha,Kumar, Raaj,Singh, G. P.
, p. 1197 - 1207 (2007/10/02)
The primary fragmentation products of Castor oil (1), namely, methyl undec-10-enoate (2) and sebacic acid (3) have been converted, using novel reactions and strategies into synthons of the type H-CC-(CH2)n-3-CH2OTHP (n=6=4; n=7=14; n=8=22; n=9=29).A surprisingly clean decarboxylative elimination of sebacic acid monoester gives methyl non-8-enoate (7), a synthon related to recefeiolide and a precursor to 4, the utility of which, has been illustrated with the synthesis of insect-pheromones of the species Grapholita molesta.Methyl dec-9-enoate (15) has been prepared by a novel and practical terminal ? to lower terminal ? degradation of 2.Compound 7 has been transformed via synthon 14 to the insect sex-pheromones of the species, Spodoptera frugiperda, Heliothis virescens and Paralobesia viteana in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxyundec-10-yne (22) readily prepared from 2, has been used to illustrate a new strategy in pheromone synthesis, namely, the use of coupling elements, leading to the preparation of bombykol in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxydodec-11-yne (29), already reported, has been transformed to vaccenic acid (30), the transposed ?-isomer of oleic acid, in good yields, thus demonstrating the use of acetylide synthons for the preparation of rare fatty acids also.
