Improved Synthesis and Deployment of (2S,3R)-2-(2Z,5Z-Octadienyl)-3-nonyloxirane, a Pheromone of the Pink Moth, Lymantria mathura
摘要:
We report two new syntheses of (2S,3R)-2-(2Z5Z-octadienyl)-3-nonyloxirane, the main sex pheromone component of the pink moth, Lymantria mathura. The key step in the first route was the construction of (Z,Z)-1-bromo-1,4-heptadiene (6), which was coupled in the final step with 2-iodomethyl-3-nonyloxirane 4 via a Grignard reaction. The second approach employed alkylation of 1,4-heptadiynyllithium with epoxy triflates 7 in ether/hexane and provided the pheromone in greater than or equal to37% overall yield from alcohol 2. The 4:1 ratio of pheromone enantiomers, reportedly the most attractive to pink moth males, can be directly crafted from appropriately selected Sharpless asymmetric epoxidation conditions.
Alkylative epoxide rearrangement. A stereospecific approach to chiral epoxide pheromones
摘要:
The alkylative rearrangement of 1,2-epoxy-3-alkanol tosylates is applied to the synthesis of chiral epoxide pheromones. Attack at the terminal carbon atom of epoxy tosylates by lithioacetylenes and cyclization of the intermediate tosyloxy alcohols produces internal epoxides in high yield. The method is stereospecific: threo-epoxy tosylates give eL's-epoxides, and erythro-epoxy tosylates yield trans-epoxides. Several diastereomerically pure epoxides were prepared in high optical purity from chiral pool intermediates derived from sugars. Pheromone components prepared include (+/-)-cis-epoxyalkene 20 and both enantiomers of cis-epoxy diene 16, a female sex pheromone component of a number of lepidopteran species. These results demonstrate that alkylative rearrangement of 1,2-epoxy-3-alkanol tosylates complements existing methods for stereoselective synthesis of epoxides, including the Payne rearrangement and Sharpless epoxidation.
Improved Synthesis and Deployment of (2<i>S</i>,3<i>R</i>)-2-(2<i>Z</i>,5<i>Z</i>-Octadienyl)-3-nonyloxirane, a Pheromone of the Pink Moth, <i>Lymantria mathura</i>
作者:Ashot Khrimian、James E. Oliver、Roger C. Hahn、Nikki H. Dees、Jeff White、Victor C. Mastro
DOI:10.1021/jf035506q
日期:2004.5.1
We report two new syntheses of (2S,3R)-2-(2Z5Z-octadienyl)-3-nonyloxirane, the main sex pheromone component of the pink moth, Lymantria mathura. The key step in the first route was the construction of (Z,Z)-1-bromo-1,4-heptadiene (6), which was coupled in the final step with 2-iodomethyl-3-nonyloxirane 4 via a Grignard reaction. The second approach employed alkylation of 1,4-heptadiynyllithium with epoxy triflates 7 in ether/hexane and provided the pheromone in greater than or equal to37% overall yield from alcohol 2. The 4:1 ratio of pheromone enantiomers, reportedly the most attractive to pink moth males, can be directly crafted from appropriately selected Sharpless asymmetric epoxidation conditions.
Alkylative epoxide rearrangement. A stereospecific approach to chiral epoxide pheromones
作者:Thomas W. Bell、James A. Ciaccio
DOI:10.1021/jo00071a026
日期:1993.9
The alkylative rearrangement of 1,2-epoxy-3-alkanol tosylates is applied to the synthesis of chiral epoxide pheromones. Attack at the terminal carbon atom of epoxy tosylates by lithioacetylenes and cyclization of the intermediate tosyloxy alcohols produces internal epoxides in high yield. The method is stereospecific: threo-epoxy tosylates give eL's-epoxides, and erythro-epoxy tosylates yield trans-epoxides. Several diastereomerically pure epoxides were prepared in high optical purity from chiral pool intermediates derived from sugars. Pheromone components prepared include (+/-)-cis-epoxyalkene 20 and both enantiomers of cis-epoxy diene 16, a female sex pheromone component of a number of lepidopteran species. These results demonstrate that alkylative rearrangement of 1,2-epoxy-3-alkanol tosylates complements existing methods for stereoselective synthesis of epoxides, including the Payne rearrangement and Sharpless epoxidation.