18681-09-9Relevant academic research and scientific papers
ENOL THIOETHERS AS ENOL SUBSTITUTES. AN ALKYLATION SEQUENCE.
Trost,Lavoie
, p. 5075 - 5090 (2007/10/02)
Ionic bromination of enol phenyl thiolethers forms predominantly to exclusively 2-(phenylthio)-3-bromo-1-alkenes, an enolonium equivalent. The allylic bromide participates in displacements with stabilized and nonstabilized nucleophiles. The ability to hydrolyze the enol thioethers to their corresponding ketones equates this sequence to an equivalence of an enolonium ion. The versatility of the sulfur in selective introduction of allylic hydroxyl and amino groups as well as the ability to directly replace the sulfur substituent by hydrogen or alkyl imparts special significance to this approach. The sequence is highly regio-and chemoselective. Applications include the synthesis of lanceol and bisabolene and the introduction of steroid side chains.
Synthesis of isoprenoid 1,5-dienes
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, (2008/06/13)
Aliphatic acids containing an isoprenoid 1,5-diene moiety are prepared in high yields by the selective gamma alkylation of α,β-unsaturated acids with allylic electrophiles. The gamma-regioselectivity of the alkylation is controlled by the use of the dicopper(I) dienolates prepared from the α,β-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.
