| 摘要 |
Aliphatic acids containing an isoprenoid 1,5-diene moiety are prepared in high yields by the selective gamma alkylation of alpha , beta -unsaturated acids with allylic electrophiles. The gamma-regioselectivity of the alkylation is controlled by the use of the dicopper(I) dienolates prepared from the alpha , beta -unsaturated acids. The method offers a particularly facile means for synthesizing isoprenoid 1,5-diene natural products such as farnesoic acid by alkylation of senecioic acid with geranyl bromide; geranoic acid by alkylation of senecioic acid with 3,3-dimethallyl bromide; and dl-lanceol by alkylation of tiglic acid with an allylic bromide derived from dl-limonene. Such products find use in the synthesis of insect pheremones, insect juvenile hormones, and components of perfumes.
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