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8-Propiolactones product

An alternative route to acrylic esters is via a (3-propiolactone intermediate. The lactone is obtained by the reaction of formaldehyde and ketene, a dehydration product of acetic acid ... [Pg.217]

Ring-opening polymerization of racemic a-methyl-/J-propiolactone using lipase PC catalyst proceeded enantioselectively to produce an optically active (S)-enriched polymer [68]. The highest ee value of the polymer was 0.50. NMR analysis of the product showed that the stereoselectivity during the propagation resulted from the catalyst enantiomorphic-site control. [Pg.249]

A 1992 patent describes the carbonylation of EO to yield /3-propiolactone using a mixture of Co2(CO)8 and 3-hydroxypyridine.982 A recent re-investigation of this system has indicated that the major product is the alternating copolymer, a polyester, catalyzed by the [Co(CO)4] anion (Scheme 24).983 The synthesis of lactones via this methodology has successfully been achieved using Lewis acidic counter-cations (Scheme 25) 984,985 a similar strategy allows /3-lactams to be... [Pg.57]

P-parinaric acid, physical properties, 5 33t P-pentenoic acid, physical properties, 5 3 It P-peroxylactones, 18 484 Beta phase titanium, 24 838 in alloys, 24 854-856 properties of, 24 840, 941 P-phellandrene, 24 493 P-picoline, 21 110 from acrolein, 1 276 uses for, 21 120 P-pinene, 3 230 24 496-497 major products from, 24 478 /-menthol from, 24 522 as natural precursor for aroma chemicals, 3 232 terpenoids from, 24 478-479 P-propiolactone, polymerization of, 14 259 P-quartz solid solution, 12 637—638 Beta ratio, in filtration, 11 329—330 Beta (P) rays, 21 285 P-scission reactions, 14 280-281 P-skytanthine, 2 101 P-spodumene solid solution, 12 638-639 P-sulfur trioxide, 23 756 P-sultones, 23 527 P-tocopherol, 25 793 P-tocotrienol, 25 793 P-vinylacrylic acid, physical properties, 5 33t... [Pg.97]

The reaction of P-propiolactone with wood can be catalysed by acid or base, to yield two different products (Figure 4.12). [Pg.96]

Palmes ED, Orris L, Nelson N Skin irritation and skin tumor production by P-propiolactone (BPL). Am Ind HygJ 23a57-264, 1962... [Pg.601]

Figure 3.9. Generalized overview of the industrial-scale manufacture of recombinant E2 classical swine fever-based vaccine, using insect cell culture production systems. Clean (uninfected) cells are initially cultured in 500-1000 litre bioreactors for several days, followed by viral addition. Upon product recovery, viral inactivating agents such as /i-propiolactone or 2-bromoethyl-iminebromide are added in order to destroy any free viral particles in the product stream. No chromatographic purification is generally undertaken as the product is substantially pure the cell culture media is protein-free and the recombinant product is the only protein exported in any quantity by the producer cells. Excipients added can include liquid paraffin and polysorbate 80 (required to generate an emulsion). Thiomersal may also be added as a preservative. The final product generally displays a shelf-life of 18 months when stored refrigerated... Figure 3.9. Generalized overview of the industrial-scale manufacture of recombinant E2 classical swine fever-based vaccine, using insect cell culture production systems. Clean (uninfected) cells are initially cultured in 500-1000 litre bioreactors for several days, followed by viral addition. Upon product recovery, viral inactivating agents such as /i-propiolactone or 2-bromoethyl-iminebromide are added in order to destroy any free viral particles in the product stream. No chromatographic purification is generally undertaken as the product is substantially pure the cell culture media is protein-free and the recombinant product is the only protein exported in any quantity by the producer cells. Excipients added can include liquid paraffin and polysorbate 80 (required to generate an emulsion). Thiomersal may also be added as a preservative. The final product generally displays a shelf-life of 18 months when stored refrigerated...
Methanolysis of 0-propiolactone with a trace of hydroxide catalyst gives a good yield of methyl 3 -hydroxypropionic acid, but with an equimolecular quantity of sodium methoxide the product is sodium 3-methoxypropionate (equation 48) (64hc(19-2)729). [Pg.386]

Reaction with ammonia and primary and secondary amines can also give two types of products, 0-hydroxyamides or amino acids (equation 49). The amide is obtained from the reaction of 0-propiolactone with ammonia in water, while the amino acid is obtained from the reaction in acetonitrile, both in good yield. 0-Lactones react very generally with both aliphatic and aromatic amines, but the type of product does not correlate with polarity of solvent or basicity of amine. Fortunately, conditions can usually be found for the formation of the desired product. [Pg.386]

The reaction of several a-amino acid esters with 0-lactones in chloroform solution gave hydroxyamide esters (equation 50), said to be useful fungicides (74JAP(K)74127918>. Enamines derived from cyclohexanone react smoothly with 0-propiolactone to give 3-(2-cyclo-hexanonyl)propionamides in reasonable yields (equation 51). No acylation of the enamine is observed. This reaction has been used as a key step in a new synthesis of 8-aza steroids (75JOC50). Cyclohexanone imines react in the same manner, except that the expected initial product cyclizes to give bicyclic lactams and enaminones (equation 52) (80T3047). [Pg.386]

The enolate ions of acetoacetic ester and other active methylene compounds react with 0-propiolactone to give the ethoxycarbonyl derivative, but the yields are generally not high. Application of this reaction to 2-ethoxycarbonyldodecanone (equation 53) has been recently patented, with the product reported to be a useful perfume intermediate (77JAP(K)77133952). The reaction is used quite widely with diketene, which gives C-acylation rather than alkylation of the enolate ion, followed by cyclization (72CPB1574). [Pg.386]

The main use of P-propiolactone has been as an intennediate in the production of acrylic acid and its esters. It has also been used for the sterilization of vaccines and blood products. [Pg.1112]

Diones are normally synthesized from /3-hydroxy acids in two steps first, conversion into carbamates by reaction with sodium cyanate, and then cyclization with thionyl chloride (Scheme 103) (54JCS839). Alternative preparations utilize oxetanes, which may be combined either with isocyanates in the presence of boron trifluoride (68JAP6808278) or with S-alkylthioureas (Scheme 104) (69ZOR1844). In the last example the initial products are imines (224) which may readily be hydrolyzed to the required diones. Similar methods can be applied to the synthesis of tetrahydro-l,3-thiazine-2,4-diones, and, for instance, the 4-oxo-2-thioxo derivative (225) is obtained from /3-propiolactone and dithiocarbamic acid (Scheme 105) (48JA1001). [Pg.1030]

Cycloaddition of ketene to chloral. Quinidine (1) catalyzes the addition of ketene to chloral to give the / -propiolactone (2) in 89% yield and in 98% ee. As expected, quinine (C.,-cpimer of 1) also catalyzes this reaction to give (R)-(-+-)-2 in 76% ee. Examination of 15 chiral tertiary amines has led to certain conclusions the chirality of the product depends on the chirality of the carbon adjacent to the amine function, and the presence or absence of a hydroxyl group [1 to the amine is unimportant in this case. Even simple amines such as 1,2-dimethylpyrrolidine or N,N-dime thyl-z-phenyle thy 1 amine are fairly effective (60 and 77% ee, respectively). [Pg.72]

Exaltolide. The key step in a new synthesis of exaltolidc (4) is the three-carbon homologation of a Grignard reagent (1) with /i-propiolactone (2) catalyzed by Cul. The product (3) is converted into 4 in two steps.1... [Pg.413]

Carboxyethylation of enamines occurs on heating with / -propiolactone. A <5-keto-carboxylic acid amide is produced directly in high yield in the absence of water165 (Scheme 65). The same product was obtained on replacing / -propiolactone by acrylic acid, and saturated carboxylic acids gave cyclohexanone and the corresponding carboxylic acid amide. [Pg.770]

For the preparation of 4-(1.2.3.4-tetrahydroquinolino)-phenol 17 three different procedures were worked out [Eqs. (6)-(8)]. 17 was prepared by reacting N-p-methoxyphenyl-anthranilic acid with acetic anhydride and subsequent saponification to l-p-methoxyphenyl-4-hydroxy-2-quinolone, reaction withPOCl3 to form l-p-methoxyphenyl-4-chloro-2-quinolone, hydrogenation to l-(p-methoxy-phenyl)-3.4-dihydro-2-quinolone, splitting the ether with HBr to l-(p-hydroxy-phenyl)3.4-dihydro-2-quinolone, and reduction with LiAlH4 [Eq. (6)J. Another synthetic possibility was the reaction of p-anilinophenol with (3-propiolactone and subsequent cyclization to l-(p-acetoxyphenyl)2.3-dihydro-4-quinolone 18. The next step, the Wolff-Kishner reduction, led directly to the desired product [Eq. (7)]. The third way, the direct amination of p-iodoanisole with 1.2.3.4-tetrahydro-quinoline and the subsequent splitting of 4-(1.2.3.4-tetrahydro-quinolino)-anisol with HBr was the best one [Eq. (8)]. Saponification of l-(p-acetoxyphenyl>2.3-... [Pg.112]

D Hondt and Lenz polymerized optically active a-phenyl-a-ethyl-/ --propiolactone anionically a racemic and an isotactic product were formed [99]... [Pg.270]

Let us now consider situation with 2 0. The dependence of Gibbs energy on composition will exhibit two minima (Fig. 26) with increasing F1 copolymer will pass from the stable range (0 < F2< a) into an unstable one (a < F2 < b) and back into a stable range (F2 > b). The system will have a Tc minimum. Copolymerizations of vinyl and cyclic monomers present examples of such behaviour. The interactions of these compounds are of repulsive character coaddition is difficult to achieve. The product is a block copolymer [214] (for example styrene-/ -propiolactone [215]). At only weakly negative co values, the minimum on the Tc—F2 curve will not occur (see Fig. 27). Two local minima will, however, appear in the AG vs. F2 plot. [Pg.325]

Macrocyclic lactones. This stannoxane serves as a template to catalyze the condensation of propiolactone to a scries of macrocyclic lactones (2). The trimer, n = 1, is the major product (22%). The related linear stannoxane Bu,Sn(OCH,CH,)2 >s ineffective for this macrocyclization of lactones. ... [Pg.462]

In the reactions of /1-propiolactone, y-valerolactone, and d-valerolactone no products could be isolated due to tarring,Lactides react with sulfur tetrafluoride, without ring opening, to give tetrafluorodioxanes and higher fluorinated dioxanes." 6-Chloro-4-hydroxycoumarin dimerizes upon reaction with sulfur tetrafluoride/hydrogen fluoride to a fluorinated spiro compound. - ... [Pg.206]

The point has been made that the conditions of p-chloroethanol formation are not the same as used for the Wacker oxidation. Cu Pd chlorine-bridged dimers are likely reactants under higher [Cl ] reaction conditions, which may lead to a different reaction mechanism. However, a second stereochemical study also obtained results consistent with trans hydroxypaUadation. When cfr-l,2-dideuteroethene is oxidized in water with PdCl2 under a CO atmosphere, the product is tran5 -2,3-dideutero-jS-propiolactone (Scheme 37). The reaction conditions were, once again, not identical with standard Wacker process conditions, since the solvent was acetonitrile water, the temperature was —25°C, the bis-ethene PdCl2 complex was used, and there was no excess Cl present. Nevertheless, it is clear that, under many reaction conditions, a trans addition of water onto ethene coordinated to Pd is the favored reaction stereochemistry. [Pg.3581]

Reactivity in the solid-state is always connected with specific motions which allow the necessary contact between the reacting groups. In most cases solid-state reactions proceed by diffusion of reactions to centers of reactivity or by nucleation of the product phase at certain centers of disorder. This leads to the total destruction of the parent lattice. If the product is able to crystallize it is highly probable that nucleation of the crystalline product phase at the surface of the parent lattice will lead to oriented growth under the influence of surface tension. In such topotactic reactions certain crystallographic directions of parent and daughter phases will coincide. Typical examples for this behaviour are the solid-state polymerizations of oxacyclic compounds such as trioxane, tetroxane or 3-propiolactone... [Pg.93]

Titanium Lewis acids effect formal [2 + 2] cycloaddition as shown in Eqs (158) [401] and (159) [402,403]. Subtly changing the reaction conditions and substrates alters the product of Eq. (159) from the cyclobutane to a dihydrobenzofuran derivative, as will be described below. The analogous hetero [2 + 2] addition of a chiral aldehyde to a silylketene proceeded stereoselectively in the presence of titanium tetrachloride to give the propiolactone, as shown in Eq. (160) [404]. The silyl group was removed by the treatment with KF. [Pg.719]


See other pages where 8-Propiolactones product is mentioned: [Pg.90]    [Pg.119]    [Pg.416]    [Pg.53]    [Pg.397]    [Pg.82]    [Pg.453]    [Pg.40]    [Pg.552]    [Pg.387]    [Pg.433]    [Pg.1104]    [Pg.387]    [Pg.2617]    [Pg.222]    [Pg.12]    [Pg.604]    [Pg.310]    [Pg.102]    [Pg.434]   
See also in sourсe #XX -- [ Pg.445 ]




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