54910-52-0

Upstream product

• 35354-39-3 cis-2-Methyl-7-octadecen 
• 113466-79-8 4-methylpentyllithium 
• 113466-78-7 (3-decyloxiran-2-yl)methyl 4-methylbenzenesulfonate 
• 51050-50-1 trans-7,8-epoxy-2-methyloctadecane 
• 22146-85-6 (Z)-deca-1,5,9-triene 
• 244771-27-5 1,10-diiodo-5(Z)-decene 
• 112-54-9 Dodecanal 
• 78389-78-3 2-bromododecanal 
• 870-63-3 prenyl bromide 
• 626-89-1 4-Methyl-1-pentanol 
• 112-29-8 1-bromo dodecane 
• 626-88-0 1-bromo-5-methylpentane 
• 35354-38-2 2-methyloctadec-7-yne 

Relevant academic research and scientific papers

SYNTHESIS OF Z-OLEFIN-CONTAINING LEPIDOPTERAN INSECT PHEROMONES

The present invention is directed to methods of synthesizing insect pheromones, particularly lepidopteran insect pheromones, their precursors and derivatives from inexpensive, readily available starting materials using olefin metathesis catalysis.

Concise syntheses of insect pheromones using Z-Selective cross metathesis

Very short synthetic routes to nine cisolefin-containing pheromones containing a variety of functionality, including an unconjugated (E,Z) diene, are reported (see scheme). These lepidopteran pheromones are used extensively for pest control, and were easily prepared using ruthenium-based Z-selective cross metathesis, highlighting the advantages of this method over less efficient ways to form Z olefins.

New synthesis of (±)-cis-disparlure, pheromone of female gypsy moth (Porthetria dispar) species

(±)-cis-Disparlure was synthesized in an overall yield of 50% via stereoselective addition of isoheptylmagnesium bromide to α-bromododecanal.

A highly stereoselective preparation of syn-1,2-diols from secondary α-allenic alcohols via iodocyclization. Synthesis of (±)-threo-L-factor and (±)-disparlure

The iodocyclization of the N-tosyl carbamates 5 of secondary α-allenic alcohols 4 is described. The reaction sequence involves the addition of iodine to the terminal olefin of the allene moiety of 5 resulting in the formation of an isomeric mixture of Z and E diiodides 6 and 7. This initial process is followed, in the same pot, by reaction of the diiodides with silver carbonate. Hydrolysis of the resulting trans imino carbonates 8 provides syn-1,2-diols 10 in highly diastereoselective (>50:1) and regioselective (>20:1) fashion. Oxazolidinones 9 are minor products that arise from the participation of the carbamate nitrogen atom in the cyclization reaction. The regioselectivity of the cyclization reaction from 6/7 to 8 is highly dependent upon the reaction solvent with the optimum results being obtained in ether/MeCN mixtures (10:1 to 50:1) or CH2Cl2. The synthetic utility of the vinyl iodo diols 10 is demonstrated by the synthesis of (±)-threo-5-hydroxy-4-decanolide (17) ((±)-threo-L-factor) and (±)-cis-7,8-epoxy-2-methyloctadecane (24) ((±)-disparlure). The key step in each synthesis involves the conversion of the vinyl iodide moiety of 10 into the alkynes 15 or 18 (from 10j and 10k, respectively) via a high-yielding dehydrohalogenation reaction.

Tritium-Labeled Enantiomers of Disparlure. Synthesis and in Vitro Metabolism

Both of the enantiomers of disparlure, the gypsy moth sex attractant, have been prepared at high specific activity (58 Ci/mmol) by homogeneous tritiation of the optically active alkenyl oxiranes.An improved preparation of the racemic disparlure is also described.The radiolabeled epoxides are cleanly converted to a single product by enzymes isolated from adult gypsy moths (Lymantria dispar).Enzymatic activity obtained from male antennae showed the highest conversion; enzymes isolated from female antennae and from male and female legs showed lower activity.The identification of the metabolite as the threo-7,8-diol is established by independent synthesis and by chemical derivatizations to the diacetate, n-butylboronate, and bis(trimethylsilyl) ether.A symmetrical epoxide analogous to disparlure is converted to a diol product at a significantly lower rate.

A NEW VARIANT OF THE SYNTHESIS OF DISPARLURE VIA ACETYLENIC INTERMEDIATES

Disparlure, the sexual feromone of the Gypsy Moth, has been prepared via the known intermediate 2-methyl-7-octadecyne, using a new constructional principle: C9+C10->C19.The so far undescribed 7-methyl-1-octyne was used as the C9 component.The advantages of this procedure consist in higher yields of disparlure and in a substantial simplification of the method of purification of 2-methyl-7-octadecyne.

SILICON IN ORGANIC SYNTHESIS. STREREOSELECTIVE SYNTHESIS OF SOME INSECT SEX PHEROMONES

Trialkylsilallyl anion is alkylated by alkyl halides to give regio- and strereo-selectively the γ-product with trans-strereochemistry at double bond.The trans-vinylsilanes are transformed strereoselectively to Z-vinyl iodides.Coupling of the vinyl idiodes with organometallic reagents gives Z-alkenes.This approach has been applied to the synthesis of several insect sex pheromones.

A New Synthesis of (Z)-7,8-Epoxy-2-methyloctadecane (Disparlure)

Alkylation of the dianion of propargyl alcohol with 1-bromodecane in Li/liq.NH3 affords tridec-2-yn-1-ol (II) which on hydrogenation in the presence of Lindlar's catalyst yields tridec-2Z-en-1-ol (III).Treatment of III with MsCl/Et3N in anhyd.CH2Cl2 at low temperature gives the mesylate (IV) which undergoes smooth coupling reaction with 1-bromo-4-methylpentane (V) to produce 2-methyloctadec-7Z-ene (VI).Reactions of VI with m-chloroperbenzoic acid in anhyd.CH2Cl2 furnishes the title compound (I).