Synthesis of isoprenoid 1,5-dienes
AssigneeUniversity of Illinois Foundation
InventorJohn A. Katzenellenbogen
Life of this patent
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Abstract
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.
Claims18
A method of synthesizing aliphatic acids containing 1,5-isoprenoid diene moieties comprising the steps of:
- a. forming a dicopper(I) dienolate of an aliphatic .alpha.,.beta.-unsaturated acid by reaction of the .alpha.,.beta.-unsaturated acid or sodium salt thereof first with lithium dialkyl amide and then with cuprous iodide;
- b. selectively alkylating the dicopper(I) dienolate at the gamma position with an allylic electrophile having the general formula ##STR26## where X .dbd. halide or sulfonate and R.sub.1 -R.sub.5 are hydrogen or C.sub.1 -C.sub.10 aliphatic or cycloaliphatic groups;
- and
- c. isolalating the alkylation production from the reaction mixture of step (b).
The method of synthesizing farnesoic acid comprising the steps of:
- a. forming the dicopper(I) dienolate of senecioic acid;
- b. selectively alkylating the dicopper(I) at the gamma position with geranyl bromide;
- and
- c. isolating farnesoic acid from the reaction mixture of step (b).
The method of synthesizing geranoic acid comprising the steps of:
- a. forming the dicopper(I) dienolate of senecioic acid;
- b. selectively alkylating the dicopper(I) dienolate at the gamma position with 3,3-dimethallyl bromide;
- and
- c. isolating geranoic acid from the reaction mixture of step (b).
The compound 2-(1'-penten-2'-yl)-4-penetenoic acid having the formula ##STR28##
The compound 3-propyl-2,6-heptadienoic acid having the formula ##STR29##
The compound 2,5-dimethyl-2-vinyl-4-hexenoic acid having the formula ##STR30##
The compound (E)-2,5,6-trimethyl-2,6-heptadienoic acid having the formula ##STR31##
The compound (E,E)-2,6-dimethyl-2,6-octadienoic acid having the formula ##STR32##
The compound (E,Z)-2,6-dimethyl-2,6-Octadienoic acid having the formula ##STR33##
The compound (E,E)-2,6-dimethyl-2,6-undecadienoic acid having the formula ##STR34##
The compound 2,4-dimethyl-2-vinyl-4-pentenoic acid having the formula ##STR35##
Dependencies are inferred from the claim text.