Allyl propionate, reaction

With a high-temperature initiator such as di-tert-butyl peroxide, copolymers of 1-octene with allyl propionate or allyl butyrate have been prepared in sealed tubes. The reaction conditions included methyl ethyl ketone as a solvent, 0.05% di-tert-butyl peroxide heated in sealed ampoules at 200°C for 4 hr. The molecular weights of the product were in the range of 600 200 [62]. 

The excess of N-chlorosuccinimide is destroyed by the addition of about 15 drops of allyl alcohol and 180 ml of water is then added with stirring. This mixture is held at 0°C for about one hour. The precipitated 16/3-methyl-1,4-pregnadiene-9o-chloro-11/3,17o,21-triol-3,20-dione-21-acetate is recovered by filtration. A solution of 250 mg of the chlorohydrin in 5 ml of 0.25N perchloric acid in methanol is stirred for about 18 hours at room temperature to produce 16/3-methyl-9o-chloro-11/3,17o,21-trihydroxy-1,4-pregnadiene-3,20-dione which is recovered by adding water to the reaction mixture and allowing the product to crystallize. Propionic anhydride is then used to convert this material to the dipropionate. 

Johnson s classic synthesis of progesterone (1) commences with the reaction of 2-methacrolein (22) with the Grignard reagent derived from l-bromo-3-pentyne to give ally lie alcohol 20 (see Scheme 3a). It is inconsequential that 20 is produced in racemic form because treatment of 20 with triethyl orthoacetate and a catalytic amount of propionic acid at 138 °C furnishes 18 in an overall yield of 55 % through a process that sacrifices the stereogenic center created in the carbonyl addition reaction. In the presence of propionic acid, allylic alcohol 20 and triethyl orthoacetate combine to give... 

Intermolecular hydroalkoxylation of 1,1- and 1,3-di-substituted, tri-substituted and tetra-substituted allenes with a range of primary and secondary alcohols, methanol, phenol and propionic acid was catalysed by the system [AuCl(IPr)]/ AgOTf (1 1, 5 mol% each component) at room temperature in toluene, giving excellent conversions to the allylic ethers. Hydroalkoxylation of monosubstituted or trisubstituted allenes led to the selective addition of the alcohol to the less hindered allene terminus and the formation of allylic ethers. A plausible mechanism involves the reaction of the in situ formed cationic (IPr)Au" with the substituted allene to form the tt-allenyl complex 105, which after nucleophilic attack of the alcohol gives the o-alkenyl complex 106, which, in turn, is converted to the product by protonolysis and concomitant regeneration of the cationic active species (IPr)-Au" (Scheme 2.18) [86]. 

The sulfone moiety was reductively removed and the TBS ether was cleaved chemoselectively in the presence of a TPS ether to afford a primary alcohol (Scheme 13). The alcohol was transformed into the corresponding bromide that served as alkylating agent for the deprotonated ethyl 2-(di-ethylphosphono)propionate. Bromination and phosphonate alkylation were performed in a one-pot procedure [33]. The TPS protecting group was removed and the alcohol was then oxidized to afford the aldehyde 68 [42]. An intramolecular HWE reaction under Masamune-Roush conditions provided a macrocycle as a mixture of double bond isomers [43]. The ElZ isomers were separated after the reduction of the a, -unsaturated ester to the allylic alcohol 84. Deprotection of the tertiary alcohol and protection of the prima-... 

Among the characterized metal homoenolates, only zinc homoenolate of alkyl propionate undergoes substitution reactions with electrophiles under suitable conditions. Two types of metal catalysts, copper(I) and metals of the nickel triad (e.g. Pd), have successfully been used to effect allylation, arylation, and vinylation reactions. 

Aldol reaction of campholenic aldehyde with propionic aldehyde yields the intermediate conjugated aldehyde, which can be selectively reduced to the saturated alcohol with a sandalwood odor. If the double bond in the cydopentene ring is also reduced, the resulting product does not have a sandalwood odor (161). Reaction of campholenic aldehyde with -butyraldehyde followed by reduction of the aldehyde group gives the allylic alcohol known commercially by one manufacturer as Bacdanol [28219-61-6] (82). 

As with inorganic solid catalysts, the most extensively studied system was acetic acid—ethanol [428,432,434,444—448]. Other alcohols used in kinetic studies were methanol [430,449,450], 2-propanol [438], 1-bu-tanol [429,431,433,451—458], allyl alcohol [459], 1-pentanol [434] and ethyleneglycol [460] besides acetic acid, the reactions of formic [450], propionic [443,461], salicylic [430,449], benzoic [453—457] and oleic acids [430,451—453] and of phthalic anhydride [462] have been reported. Investigation of a greater variety of reactants is reported in only one paper [463] six alcohols (C4, Cs and C8) and five acids (mainly dicarboxylic were studied. Transesterification kinetic studies were performed with ethyl formate [437,439,441], isobutyrate [437,439—441] acetate [402, 435—437,439—442], methoxyacetate [441] and acrylate [403,404,464, 465] the alcohols used were methanol [402,435,437,439—442,450],... 

The Johnson Claisen rearrangement,31 also called the ortho ester Claisen rearrangement, involves the reaction of an allylic alcohol with an ortho ester, often triethyl orthoacetate, in the presence of a carboxylic acid such as propionic acid, usually at temperatures between 120 and 140 JC (Scheme 3).1 The intermediate kctcnc acetal rearranges stereoselectively. 

In 1997, the first truly catalytic enantioselective Mannich reactions of imines with silicon enolates using a novel zirconium catalyst was reported [9, 10]. To solve the above problems, various metal salts were first screened in achiral reactions of imines with silylated nucleophiles, and then, a chiral Lewis acid based on Zr(IV) was designed. On the other hand, as for the problem of the conformation of the imine-Lewis acid complex, utilization of a bidentate chelation was planned imines prepared from 2-aminophenol were used [(Eq. (1)]. This moiety was readily removed after reactions under oxidative conditions. Imines derived from heterocyclic aldehydes worked well in this reaction, and good to high yields and enantiomeric excesses were attained. As for aliphatic aldehydes, similarly high levels of enantiomeric excesses were also obtained by using the imines prepared from the aldehydes and 2-amino-3-methylphenol. The present Mannich reactions were applied to the synthesis of chiral (3-amino alcohols from a-alkoxy enolates and imines [11], and anti-cc-methyl-p-amino acid derivatives from propionate enolates and imines [12] via diastereo- and enantioselective processes [(Eq. (2)]. Moreover, this catalyst system can be utilized in Mannich reactions using hydrazone derivatives [13] [(Eq. (3)] as well as the aza-Diels-Alder reaction [14-16], Strecker reaction [17-19], allylation of imines [20], etc. 

Benzyl halides have been reported to react with nickel carbonyl to give both coupling and carbonylation (59). Carbonylation is the principal reaction in polar nonaromatic solvents, giving ethyl phenylacetate in ethanol, and bibenzyl ketone in DMF. The reaction course is probably similar to that of allylic halides. Pentafluorophenyl iodide gives a mixture of coupled product and decafluorobenzophenone. A radical mechanism has been proposed (60). Aromatic iodides are readily carbonylated by nickel carbonyl to give esters in alcoholic solvents or diketones in ethereal solvent (57). Mixtures of carbon monoxide and acetylene react less readily with iodobenzene, and it is only at 320° C and 30 atm pressure that a high yield of benzoyl propionate can be obtained (61). Under the reaction conditions used, the... 

Several studies of O2 uptake by pre-adsorbed 77-allyl species confirm that a surface complex is initially formed. With a surface 7r-allyl concentration of 50% saturation (to minimize reactions between w-allyls and oxidation intermediates), i.r. spectra of the intermediate were compared with those obtained from separate adsorption of molecules which were likely candidates. Kugler and Kokes concluded from this approach that the intermediate was indeed acrolein, on account of a 1 1 correspondence of the spectra. Other candidates studied were allene, propanal, propan-l-ol, propan-2-ol, acetone, propionic and acetic acids, and acetaldehyde. Only the spectra for acrolein resembled that produced from propene plus O2. 

Kubokawa et al also studied oxidation by N2O of the 77-allyl species from propene. In this case only propionate species were detected, N2O producing little scission of C—C bonds. Such differences between O2 and N2O were believed due to the fact that in the former case OJ was the active species whereas in the latter it was 0. Although some recent work on N2O decomposition over ZnO was interpreted to show that electron transfer did not occur in this reaction, evidence in favour of 0 formation is presented by Cunningham et alP Thus 0 from N2O is postulated as the active species in surface oxidative dehydrogenation of primary and secondary alcohols over ZnO, the first reaction step being a-hydrogen abstraction. 

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