2- butene-1,4-diol, reaction

For liquid reactions (192 product species, 450 data) Fig. 6.7 provides data for liquid, liquid-liquid, gas-liquid, gas-liquid-solid reactions. Over 80% of the data lie within the factor-of-ten bands. Data lying outside the factor-of-ten bands are acetaldehyde (-) via oxidation acetone (-r-r) via oxidation adipic acid (-) via oxidation aldol (-) via condensation alkylate (—) via alkylation amino undeca-noic acid (-) via hydrolysis benzoic acid (-) via oxidation butanol (-) via carbony-lation butene diol (-) via hydrogenation butyl acetate (-) via alkylation cellulose... 

Percent product distribution Methylvinylketone (MVK) 49.0 1.1, metha-croleine (MAC) 44.3 1.6, 3-methyl-fiiran (MFU) 6.7 0.6 for isoprene mole fractions 400 ppm. The ratio of MVK to MAC under these conditions was 1.1 0.6. In the presence of NO the ratio is close to 1.4 [4]. Computer simulations based on our results for methylsubstituted 1-butenes showed that the observed [MVK]/[MAC] ratios are obtained with essentially equal probabilities for OH attack at the two double bonds of isoprene. This result contradicts predictions based on OH reaction rate coefficients for various methylsubstituted butenes [5]. Similar to results obtained for the 1-butenes, diols and hydroxy carbonyl compounds were found in small yields among the products. These are not included in the above product distribution because they are difficult to quantify. ... 

The reaction of a halide with 2-butene-1,4-diol (104) affords the aldehyde 105, which is converted into the 4-substituted 2-hydroxytetrahydrofuran 106, and oxidized to the 3-aryl-7-butyrolactone 107[94], Asymmetric arylation of the cyclic acetal 108 with phenyl triflate[95] using Pd-BINAP afforded 109, which was converted into the 3-phenyllactone 110 in 72% ee[96]. Addition of a molecular sieve (MS3A) shows a favorable effect on this arylation. The reaction of the 3-siloxycyclopentene 111 with an alkenyl iodide affords the. silyl... 

Ma.nufa.cture. Butenediol is manufactured by partial hydrogenation of butynediol. Although suitable conditions can lead to either cis or trans isomers (111), the commercial product contains almost exclusively iVj -2-butene-l,4-diol Trans isomer, available at one time by hydrolysis of l,4-dichloro-2-butene, is unsuitable for the major uses of butenediol involving Diels-Alder reactions. The Hquid-phase heat of hydrogenation of butynediol to butenediol is 156 kj/mol (37.28 kcal/mol) (112). 

Acetylene is condensed with carbonyl compounds to give a wide variety of products, some of which are the substrates for the preparation of families of derivatives. The most commercially significant reaction is the condensation of acetylene with formaldehyde. The reaction does not proceed well with base catalysis which works well with other carbonyl compounds and it was discovered by Reppe (33) that acetylene under pressure (304 kPa (3 atm), or above) reacts smoothly with formaldehyde at 100°C in the presence of a copper acetyUde complex catalyst. The reaction can be controlled to give either propargyl alcohol or butynediol (see Acetylene-DERIVED chemicals). 2-Butyne-l,4-diol, its hydroxyethyl ethers, and propargyl alcohol are used as corrosion inhibitors. 2,3-Dibromo-2-butene-l,4-diol is used as a flame retardant in polyurethane and other polymer systems (see Bromine compounds Elame retardants). 

The application of the AE reaction to kinetic resolution of racemic allylic alcohols has been extensively used for the preparation of enantiomerically enriched alcohols and allyl epoxides. Allylic alcohol 48 was obtained via kinetic resolution of the racemic secondary alcohol and utilized in the synthesis of rhozoxin D. Epoxy alcohol 49 was obtained via kinetic resolution of the enantioenriched secondary allylic alcohol (93% ee). The product epoxy alcohol was a key intermediate in the synthesis of (-)-mitralactonine. Allylic alcohol 50 was prepared via kinetic resolution of the secondary alcohol and the product utilized in the synthesis of (+)-manoalide. The mono-tosylated 3-butene-1,2-diol is a useful C4 building block and was obtained in 45% yield and in 95% ee via kinetic resolution of the racemic starting material. 

The cyclohexyloxy(dimethyl)silyl unit in 8 serves as a hydroxy surrogate and is converted into an alcohol via the Tamao oxidation after the allylboration reaction. The allylsilane products of asymmetric allylboration reactions of the dimethylphenylsilyl reagent 7 are readily converted into optically active 2-butene-l, 4-diols via epoxidation with dimethyl dioxirane followed by acid-catalyzed Peterson elimination of the intermediate epoxysilane. Although several chiral (Z)-y-alkoxyallylboron reagents were described in Section 1.3.3.3.3.1.4., relatively few applications in double asymmetric reactions with chiral aldehydes have been reported. One notable example involves the matched double asymmetric reaction of the diisopinocampheyl [(Z)-methoxy-2-propenyl]boron reagent with a chiral x/ -dialkoxyaldehyde87. 

In the Mukaiyama variation of the aldol reaction, 3-benzoyloxy-2-trimethylsiloxy-l-butene adds to 2-methylpropanal in a stereoselective manner. Best results are obtained in the presence of titanium(IV) chloride, giving the adducts 9/10 in a diastereomeric ratio of 92 8. Hydrolysis of the benzoyl group and subsequent oxidative cleavage of the 1,2-diol moiety liberates / -hy-droxycarboxylic acids593. 

Cis 2-butene (48a) thus yields the meso 1,2-diol (47), i.e. the overall hydroxylation is stereoselectively SYN, as would be expected from Os—O cleavage in a necessarily cis cyclic ester (46). The disadvantage of this reaction as a preparative method is the expense and toxicity of 0s04. This may, however, be overcome by using it in catalytic quantities only, but in association with H202 which re-oxidises the osmic acid, (HO)2OsOz, formed to 0s04. 

The synthesis of 9-(l,4-dihydroxybut-2-oxy)purines commenced with 2-butene-l,4-diol (1004) and via 1005 to 1006, which upon reaction with 1007 gave 1011 and then, upon hydrolysis, the racemic alkoxyamine 1012. The chiral derivatives commenced with the enantiomers of malic acid (1009) through 1010 to 1008, as shown in the scheme. Treatment of 1012 with 996 and further transformations followed almost the same sequence as before to give 1013. 

Some additional examples, where the stereochemical outcome of the cycloaddition to chiral alkenes has been explained in terms of the Honk—Jager model, should also be mentioned. The diastereomer ratio found in the reaction of y-oxy-a,p-unsamrated sulfones (166), with Morita-Baylis-Hillman adducts [i.e., ot-(a -hydro-xyalkyl)-acrylates (167)] (Scheme 6.27), with dispiroketal-protected 3-butene-l,2-diol (168), and with a,p-unsamrated carbonyl sugar and sugar nitroolefin (169) derivatives, all agree well with this model. 

Dihydromuscimol (49) is a conformationally restricted analogue of the physiologically important neurotransmitter y-aminobutyric acid (GABA) and has been prepared using the cycloaddition of dibromoformaldoxime to A-Boc-allylamine followed by N-deprotection with sodium hydroxide (Scheme 6.52) (278). The individual enantiomers of dihydromuscimol were obtained by reaction of the bromonitrile oxide with (5)-( + )-l,2-0-isopropylidene-3-butene-l,2-diol, followed by separation of the diastereoisomeric mixture (erythro/threo 76 24), hydrolysis of respective isomers, and transformation of the glycol moiety into an amino group (279). 

Oxidation of Bis (1-methyl-2-acetoxypropyl) selenide in the Presence of 2-Butene. The only product of the reaction was 3-acetoxy-l-butene. No epoxides and only traces of diols were detected in the reaction product. Approximately 0.85 mole of 3-acetoxy-l-butene was produced per mole of peracetic acid consumed, and approximately 90% of the original selenide was recovered unchanged. 

Dihydro-1,3-dioxepins (298) are prepared by the reaction of m-butene-1,4-diols with aldehydes, and a similar route gave the dithia derivative (299) which was converted into the more unsaturated compound (301) via (300) (76TL1251). 

When either an alcohol or an amine function is present in the alkene, the possibility for lactone or lactam formation exists. Cobalt or rhodium catalysts convert 2,2-dimethyl-3-buten-l-ol to 2,3,3-trimethyl- y-butyrolactone, with minor amounts of the 8-lactone being formed (equation 51).2 In this case, isomerization of the double bond is not possible. The reaction of allyl alcohols catalyzed by cobalt or rhodium is carried out under reaction conditions that are severe, so isomerization to propanal occurs rapidly. Running the reaction in acetonitrile provides a 60% yield of lactone, while a rhodium carbonyl catalyst in the presence of an amine gives butane-1,4-diol in 60-70% (equation 52).8 A mild method of converting allyl and homoallyl alcohols to lactones utilizes the palladium chloride/copper chloride catalyst system (Table 6).79,82 83... 

Similarly, 2-phenylsulfinylmethyl-substituted 4,7-dihydro-l,3-dioxepin was prepared by the reaction of r-butene-2,3-diol with 2.2equiv of sodium hydride and l-phenylsufinyl-2-phenylsulfanylethylene <2005TL1035>. 

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