4891-79-6

Upstream product

• 106-28-5 Farnesol 
• 40716-66-3 (E)-3,7,11-trimethyl-1,6,10-dodecatrien-3-ol 
• 76280-88-1 2-methyl-6-keto-6-(4-methyl-3-cyclohexen-1-yl)-2-hexene 
• 2065-66-9 methyl-triphenylphosphonium iodide 
• 18478-88-1 4-(4-Methylcyclohex-3-en-1-yl)-pent-4-enal 
• 24470-78-8 isopropyltriphenylphosphonium iodide 
• 63023-43-8 (Z,E)-Farnesyldiphenylphosphat 
• 56194-28-6 3,7,11-trimethyl-2ξ,6E,10-dodecatrien-1-ol 
• 19493-09-5 Methylenetriphenylphosphorane 
• 13170-43-9 (trimethylsilyl)methylmagnesium chloride 
• 920-39-8 isopropylmagnesium bromide 
• 85895-24-5 1-methyl-4-(6-methyl-5-(phenylthio)-1,5-heptadien-2-yl)cyclohexene 
• 89111-65-9 2(E),6(E)-farnesyl iodide 
• 89111-66-0 2(Z),6(E)-farnesyl iodide 

Relevant academic research and scientific papers

Heteropoly acid catalyzed cyclization of nerolidol and farnesol: Synthesis of α-bisabolol

Heteropoly acid H3PW12O40 is an active and environmentally friendly homogeneous catalyst for the synthesis of α-bisabolol, a high-priced and highly demanded ingredient for the fragrance, cosmetic and pharmaceutical industries, starting from more abundant biomass-based sesquiterpenic alcohols. The solvent nature remarkably affects the reaction pathways and product selectivity. In acetone solutions, α-bisabolol can be obtained in 55-60% GC yields from nerolidol and 60-70% GC yields from farnesol at complete substrate conversions, which are probably the best results ever reported for these reactions. α-Bisabolol synthesized by this method contains no farnesol, which is a potentially allergenic compound and should be avoided in the commercially used α-bisabolol. This advantage is especially important because the distillative separation of α-bisabolol and farnesol is a troublesome task. The catalyst shows high turnover numbers and operates under mild nearly ambient conditions.

Termite trail attractants: New synthesis of racemic (E)-α-, (Z)-α- and β-bisabolenes

Racemic (E)-α-bisabolene (E)(1) was synthetized starting from 4-methyl-3-cyclohexenecarboxylic acid (3) by a reaction sequence involving the Pd(0)-catalyzed cross-coupling reaction between the (E)-2-methyl-1-alkenyltrimethylstannane 8 and 3-methyl-2-buten-1-yl acetate (9). Three different procedures, in which a common precursor was used as key intermediate, were tested for the synthesis of racemic (Z)-α-bisabolene (Z)(1). The best one, which involved the reaction between bromide 18 and lithium dialkenylcuprate 19, afforded a mixture of (Z)- and (E)-1 in a 93:7 molar ratio, respectively. Finally, racemic β-bisabolene (2) was synthetized by a simple reaction sequence involving the Zr-promoted methylenation of ketone 22 prepared from 3.

CYCLIZATION OF SOME LINEAR TERPENOLS INITIATED BY "ACTIVATED" DMSO

It was shown that the acylhydroxysulfonium salt generated in situ from DMSO and trifluoroacetic anhydride causes low-temperature cyclization of geraniol, linalool, and nerol in an aprotic medium to a mixture of p-menthane monoterpenoids, and the maximum yield is obtained in the case of the last two terpenols.A similar result was obtained for E-nerolidol.

CHIRAL LEAVING GROUP: ASYMMETRIC SYNTHESIS OF LIMONENE AND BISABOLENE

The biogenetic-type asymmetric synthesis of limonene and bisabolenes is described.As model studies for the present asymmetric synthesis, the cyclization of catechol, biphenol and binaphthol mononeryl ethers 1, 4, and 5, with organoaluminium reagents are executed to furnish limonene as a major product.Since the reaction of 1, 4, and 5 has proved to proceed much faster than that of neryl phenyl ether under the similar conditions, the rate acceleration is attributed to the novel metal-anchimeric assistance of the aluminium reagents bound with the neighboring hydroxyl group for effecting the generation of the allyl cathion.This anchimeric effect is utilized for the enantioselective cyclization of (R)-(+)-1,1'-bi-2-naphthol mononeryl ether (8) upon treatment with modified aluminium reagent 9 to produce limonene with high optical purity (77percent ee).In a similar fashion, (R)-(+)-binaphtol (Z,Z)-monofarnesyl ether 16a undergoes the enantioselective cyclization to give β-bisabolene in 76percent ee.

AN ELECTROCHEMICAL METHOD SPECIFICALLY DIRECTED TO THE PREPARATION OF DL-BISABOLOL FROM DL-NEROLIDOL

A product-selective electrosynthesis of dl-bisabolol from dl-nerolidol was accomplished by a constant current electrolysis in commercial acetone containing a small amount of LiClO4

CHEMISTRY OF THE ORGANOSILICON COMPOUNDS-165 2-TRIMETHYLSILYL-METHYL-1, 3-BUTADIENE-A VERSATILE BUILDING BLOCK FOR TERPENE SYNTHESIS

Two types of synthetically useful reactions of 2-trimethylsilylmethyl-1,3-butadiene (7) are discussed.Reactions of 7 with acid chlorides, aldehydes, ketones and acetals activated by a Lewis acid give isoprenylated compounds, while 7 undergoes the Diels-Alder reaction whit dienophiles.High regiospecificity of the reaction qualifies 7 for a versatile building block of terpene synthesis.

PHOTOCHEMICAL TRANSFORMATIONS-III; ORGANIC IODIDES (Part 3): GERANYL AND NERYL IODIDES AND 2(E),6(E)- AND 2(Z),6(E)-FARNESYL IODIDES

Solution photolysis of geranyl and neryl iodides, and 2(E),6(E)- and 2(Z),6(E)-farnesyl iodides has been carried out.Products arising from simple elimination as well as ?-participation are formed.Thus, both geranyl and neryl iodides furnished, besides some unidentified compounds, myrcene, cis-ocimene, limonene and terpinolene, though in different proportions.Likewise, the sesquiterpene analogues yielded different amounts of trans-β-farnesene, β-bisabolene, trans-α-bisabolene and ar-curcumene.Results have been discussed in terms of ionic intermediates.

ENOL THIOETHERS AS ENOL SUBSTITUTES. AN ALKYLATION SEQUENCE.

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.

HIGHLY REGIOSELECTIVE DIELS-ALDER REACTIONS OF 2-TRIMETHYLSILYLMETHYL-1,3-BUTADIENE CATALYZED BY A LEWIS ACID AND APPLICATIONS TO SYNTHESES OF TERPENES

2-Trimethylsilylmethyl-1,3-butadiene undergoes highly regioselective Diels-Alder reactions with dienophiles such as acrolein and methyl vinyl ketone catalyzed by aluminium chloride in which the "para" isomers are obtained almost exclusively.The adducts are converted readily to a variety of naturally occurring mono and sesquiterpenes.