Efficient asymmetric synthesis of long chain methyl-branched hydrocarbons, components of the contact sex pheromone of females of the cerambycid beetle, Neoclytus acuminatus acuminatus
作者:Jan E. Bello、Jocelyn G. Millar
DOI:10.1016/j.tetasy.2013.05.021
日期:2013.7
Both enantiomers of 7-methylheptacosane and 7-methylpentacosane, the major components of the female-produced contact sex pheromone of the red-headed ash borer beetle (Neoclytus acuminatus accuminatus) were synthesized in 62-68% overall yield (six steps) via alkynylation of the triflate of a shared chiral alcohol intermediate (R)- or (S)-2-methyloctanol. The enantiomers of the shared intermediate were prepared via acylation and subsequent asymmetic methylation of (R)- and (S)-4-isopropyloxazolidin-2-one chiral auxiliaries, respectively. The methodology can be readily adapted for the preparation of analogues with any desired chain length and methyl branch positions. (C) 2013 Elsevier Ltd. All rights reserved.