Butyrolactone, Table

Butyrolactone. y-Butyrolactone [96-48-0] dihydro-2(3H)-furanone, was fkst synthesized in 1884 via internal esterification of 4-hydroxybutyric acid (146). In 1991 the principal commercial source of this material is dehydrogenation of butanediol. Manufacture by hydrogenation of maleic anhydride (147) was discontinued in the early 1980s and resumed in the late 1980s. Physical properties are Hsted in Table 4. 

Pyrrohdinone (2-pyrrohdone, butyrolactam or 2-Pyrol) (27) was first reported in 1889 as a product of the dehydration of 4-aminobutanoic acid (49). The synthesis used for commercial manufacture, ie, condensation of butyrolactone with ammonia at high temperatures, was first described in 1936 (50). Other synthetic routes include carbon monoxide insertion into allylamine (51,52), hydrolytic hydrogenation of succinonitnle (53,54), and hydrogenation of ammoniacal solutions of maleic or succinic acids (55—57). Properties of 2-pyrrohdinone are Hsted in Table 2. 2-Pyrrohdinone is completely miscible with water, lower alcohols, lower ketones, ether, ethyl acetate, chloroform, and benzene. It is soluble to ca 1 wt % in aUphatic hydrocarbons. 

A number of other N-substituted 2-pyrroHdinones have been offered commercially or promoted as developmental products. These materials offer different and sometimes unique solvency properties. AH are prepared by reaction of butyrolactone with suitable primary amines. Principal examples are Hsted in Table 4. 

Various lithium salts and butyrolactone or PC—DME mixtures are usually used as electrolytes. The close competitive performance of CF and MnO cathodes is evidenced in Table 3. The constmction of cells is also similar for the two systems. In addition to uses mentioned for the lithium manganese dioxide system, some unique apphcations such as lighted fishing bobbers have been developed for the Japanese market. 

The use of an ester as an anion-stabilizing group for a lithiated epoxide was demonstrated by Eisch and Galle (Table 5.5, Entry 11). This strategy has been extended to a,P-epoxy-y-butyrolactone 191, which could be deprotonated with LDA and trapped in situ with chlorotrimethylsilane to give 192, which was used in a total synthesis of epolactaene (Scheme 5.45) [69], The use of a lactone rather than a... 

In the recently reported reaction of differently substituted p-, y-, and 5-lactones 20 [80], 20 mol% of Ti(OiPr)4 proved sufficient to obtain the corresponding p-, y-, and 5-hydro-xyalkyl cydopropanols 21 in 60—70% yield (Scheme 11.5, Table 11.3, entries 1—3). However, 36 mol% of the titanium reagent was found to be necessary to obtain N-protected (aminohydroxyalkyl)cyclopropanols (Table 11.3, entries 5 and 6) from the corresponding 2-N-Boc- and 3-N-Cbz-2-butyrolactones in yields of 65% and 70%, respectively. 

Polymer Solubility. The modified polymers were soluble in DMSO, dimethylacetamide, dimethylformamide and formic acid. They were insoluble in water, methanol and xylene. Above about 57% degree of substitution, the polymers were also soluble in butyrolactone and acetic acid. Solubility parameters were determined for each polymer by the titration procedure as described in the literature (65). The polymer was dissolved in DMSO and titrated with xylene for the low end of the solubility parameter and a second DMSO solution was titrated with water for the high end of the solubility parameter range. These solubility parameters and some other solubility data are summarized in Table II. 

An effective reagent for this is RuCyaq. IO(OH)3/CCl -CH3CN, used for oxidation of the lactone (2R,3R,4R)-2-methyl-2-phenylthio-3-methoxycarbonyl-methyl-4-(2 -tert-butyl-diphenylsilyloxy)ethyl-y-butyrolactone to the sulfonyl analogue (Fig. 5.16) other oxidations are listed in Table 5.2 [107]. 

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... 

However, for certain applications non-aqueous solvents have their advantages. Uni-univalent electrolytes dissolved at low to moderate concentrations in solvents with a relative permittivity larger than, approximately, 30 are completely dissociated into ions. Of the solvents on the List, methanol, glycols, glycerol, formic acid, ethylene and propylene carbonate, 4-butyrolactone, ethanolamine, 2-cyanopyridine, acetonitrile, nitromethane and -benzene, the amides, whether N-substituted or not, dimethyl sulfoxide, sulfolane, dimethyl sulfate, and hexamethyl phosphoramide have s > 30 at ambient conditions (Table 3.5). Most of these solvents have, indeed, been used in electrochemical processes. 

Solvents that meet all or most of the criteria are propylene carbonate, dimethyl sulfoxide, 4-butyrolactone, acetonitrile, sulfur dioxide, thionyl chloride, and phosphorus oxychloride. Certain other solvents, with fairly low s values, such as tetrahydrofuran, dimethoxyethane, and 1,3-oxolane are used in conjunction with a high s solvent, in order to reduce the viscosity without impairing excessively the other desirable properties of the co-solvent. All these solvents are on the List, with properties shown in the tables mentioned. Commercial implementation of such batteries has been highly successful, with energy densities of primary dischargeable batteries of 0.3 W h g 1 or 0.5 W h cm 3 and a self discharge rate of < 2% per year of the open-circuit battery being achieved. 

As shown in Table 4, the real promise of succinic acid lies in its derivatives. A DOE-funded collaboration among Oak Ridge National Laboratory Argonne National Laboratory Pacific Northwest National Laboratory National Renewable Energy Laboratory and Applied CarboChemicals, Inc. investigated succinic acid derivatives such as tetra-hydrofuran, 1,4-butanediol, y-butyrolactone, and N-methyl pyrrolidone. More recently, Applied Carbochemicals has pursued succinate salts that can serve as de-icers and herbicide additives (40,41). 

The monomers that have been used for the synthesis include glycolide, lactide, (3-propiolactone, (3-butyro lactone, y-butyrolactone, 6-valerolactone, e-caprol-actone, l,5-dioxepan-2-one, pivalolactone, l,4-dioxane-2-one, 2-methylene-1, 3-dioxolane, 2-methylene-l, 3-dioxepane, etc. The structures of some of these monomers are given in Table 1. 

The silver-catalyzed synthesis of methylene butyrolactones has been known for a long time 39 the field was revived by Genet more recently.40 Scheme 12.21 shows that the silver(I) catalysis required 10 mol% of catalyst and 110°C, but then gave a very good yield of product. Scheme 12.22 displays the corresponding investigation of Genet and coworkers the different conditions and catalysts tested are shown in Table 12.15. 

Table 7 demonstrates that aromatic, aliphatic, and a, 3-unsaturated ketones or aldehydes can be used as electrophiles. With regard to the cyclopropane substituents, R1 has to be hydrogen for the synthesis of y-butyrolactones 200, but other examples (vide infra) show that the crucial C-C-bond forming step also proceeds with Rl H. 

The reaction proceeds via the normal six-membered transition state mechanism of ester elimination. The intermediate chlorobutyric acid yielded butyrolactone through participation of the COOH group under the reaction conditions. The pure chlorobutyric acid was pyrolyzed and gave butyrolactone in quantitative yield. The mechanism is similar to that of bromobutyric acid pyrolysis (equation 76). The data are shown in Table 23. 

IM-COOH-OH cooperation. Polymers such as poly(4(5)-vinylimidazole-co-7-vinyl-7-butyrolactone), poly(IM-la), and poly(4(5)-vinylimidazole-co-acrylic acid-covinyl alcohol) derived from poly(4(5)-vinylimidazole-co-methyl acrylate-co-vinyl acetate), both of which contain imidazole, carboxylic acid and hydroxyl moieties are synthesized and studied as a model of a-chymotrypsin (29). The former has a relatively ordered sequence and the latter has a random one. Results are tabulated in Table 11. The polymers cited in the Tabel contain a similarly low quantity of imidazole moiety, so that the cooperation of two subsequent imidazole moieties need not be discussed. Polymers such as L-84, L-68, M-83 and A-84 have higher catalytic activities than the polymer V-82. This suggests that the catalytic activity of the imidazole moiety in the polymers is much promoted by the carboxylate moiety in the polymers. The catalytic activities of L-84 and L-68 which have an ordered sequence are more than twice as high as that of M-83, having a random sequence. From these results it is concluded that the introduction of the hydroxyl moiety which has little cooperative effect on the imidazole moiety in V-82 in this reaction conrfition into imidazole and carboxylate — containing polymer, increases... 

Table I. Rate Constants for Degradation of Methyl Guthion in 2V-Methyl-2-pyrrolidone and Butyrolactone...

Table V. Methyl Guthion in Butyrolactone Containing No Epichlorohydrin...

We examined the representative esters, y-butyrolactone (BL), methyl formate (MF), and methyl acetate (MA). Figures 16 and 17 show FTIR spectra measured (ex situ) from noble metal electrodes polarized to low potentials in LiC104 solutions of BL and MF, respectively [30,39], As shown in these figures, at the onset reduction potential of around 1.3-1.2 V (Li/Li+), stable surface films precipitate on the electrode surfaces. Table 1 shows the spectral analysis for the surface films formed on noble metals at low potentials in BL. The conclusion drawn from the spectroscopic study is that the major surface compound formed is the dilithiated cyclic P-keto ester, which is similar to the electrolysis product of BL in TAA salt solutions (Scheme 2). 

The most important esters in connection with Li batteries are y-butyrolactone (BL) and methyl formate (MF). Li is apparently stable in both solvents due to passivation. Electrolysis of BL on noble metal electrodes produces a cyclic 0-keto ester anion which is a product of a nucleophilic reaction between a y-butyrolactone anion (produced by deprotonation in position a to the carbonyl) and another y-BL molecule. FTIR spectra measured from Li electrodes stored in y-BL indicate the formation of two major surface species the Li butyrate and the dilithium cyclic P-keto ester dianion. The identification of these products and related experimental work is described in detail in Refs. 150 and 189. Scheme 3 shows the reduction patterns of y-BL on lithium surfaces (also see product distribution in Table 3). In the presence of water, the LiOH formed on the Li surfaces due to H20 reduction attacks the y-BL nucleophilically to form derivatives of y-hydroxy butyrate as the major surface species [18] [e.g., LiO(CH2COOLi)]. We have evidence that y-BL may be nucleophilically attacked by surface Li20, thus forming LiO(CH2)3COOLi, which substitutes for part of the surface Li oxide [18]. MF is reduced on Li surfaces to form Li formate as the major surface species [4], LiOCH3, which is also an expected reduction product of MF on Li, was not detected as a major component in the surface films formed on Li surfaces in MF solutions [4], The reduction paths of MF on Li and their product analysis are presented in Scheme 3 and Table 3. 

TABLE 2. Physical properties of polyimides as liquid crystal aligning films prepared by heating A-methyl-pyrrolidone and y-butyrolactone, 8 2, respectively, with polyamic acids described in Table 1. 

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