Butyrolactone, 5-methyl

DL-4-Methyl-2-oxetanone ( )-4-Methyl-2-oxetanone. See p-Butyrolactone Methyl oxide. See Dimethyl ether Methyloxirane S(-)-Methyloxirane. See Propylene oxide... 

These include chloroethylene carbonate (Cl-EC), vinylene carbonate (VC), ethylene sulfite (ES), propylene sulfite (PS), fluoroethylene sulfite (EEC), a-bromo-y-butyrolactone, methyl chloroformate, f-butylene carbonate (f-BC), and 12-crown (12-C-4). In addition to these additives, co-solvents, such as dimethylsulfoxide (DMSO), diethoxymethane (DEM), dimethoxymethane (DMM), and diethoxyethane (DEE) are also effective for stable SEI formation in PC-based solutions. The molecular structures of these additives and co-solvents are summarized in Figure 13. It seems that all these additives give stable SEI layers on graphite surface ... 

Naji et al. [46] investigated new halogenated additives such as a-bromo-y-butyrolactone, methyl chloroformate, etc., to PC-based electrolytes to improve cycling performance. 

Methyl-2-Pyrrolidinone. N-Meth5l-2-pyrrohdinone [872-50-4] (44) (NMP or methyl-2-pyrrohdone, M-Pyrol) was fkst reported in 1907 as prepared by alkylation of 2-pyrrohdinone with methyl iodide (81). The present commercial route, ie, condensation of butyrolactone with methylamine, was first described in 1936 (50). 

Chemically, wood tar is a complex mixture that contains at least 200 individual compounds, among which the foUowing have been isolated (1) 2-methoxyphenol, 2-methoxy-4-ethylphenol, 5-meth5i-2-methoxyphenol, 2,6-x5ienol, butyric acid, crotonic acid, 1-hydroxy-2-propanone, butyrolactone, 2-methyl-3-hydroxy-4JT-pyran-4-one, 2-methyl-2-propenal, methyl ethyl ketone, methyl isopropyl ketone, methyl furyl ketone, and 2-hydroxy-3-methyl-2-cyclopenten-l-one. 

The mechanism of this reaction has been studied by several groups [133,174-177]. The consensus is that interaction of ester with the phenolic resole leads to a quinone methide at relatively low temperature. The quinone methide then reacts rapidly leading to cure. Scheme 11 shows the mechanism that we believe is operative. This mechanism is also supported by the work of Lemon, Murray, and Conner. It is challenged by Pizzi et al. Murray has made the most complete study available in the literature [133]. Ester accelerators include cyclic esters (such as y-butyrolactone and propylene carbonate), aliphatic esters (especially methyl formate and triacetin), aromatic esters (phthalates) and phenolic-resin esters [178]. Carbamates give analogous results but may raise toxicity concerns not usually seen with esters. 

NaBH4, H2O, pH 5-8, 20°, 20 min, 80-95% yield. The by-product, 5-methyl-7-butyrolactone, is water soluble and thus easily removed. 

Recently, it was found that the addition of benzylamine to 2-(5//)-furano-3-ylmethanesulfonate 280 (X = O—SOaMe) in methanol afforded a 7 1 mixture of the trans- and cw-methyl-A-benzyl-2-hydroxymethylaziridine-2-carboxylates 281 and 282, respectively (00TL3061). Treatment of 281 with benzyl alcohol in the presence of BF3 OEta furnished, after hydrolysis, rac-cw-amino-a-hydroxy-/3-butyrolactone 284 (Scheme 74). 

The synthesis of 4-alkyl-y-butyrolactones 13 and 5-alkyl-<5-valerolactones 14 can be achieved in high enantiomeric excess by alkylation of ethyl 4-oxobutanoate and ethyl 5-oxopentanoate (11, n = 2, 3). The addition of diethylzinc, as well as dimethylzinc, leads to hydroxy esters 12 in high optical purity. When methyl esters instead of ethyl esters are used as substrates, the enantioselectivity of the addition reaction is somewhat lower. Alkaline hydrolysis of the hydroxy esters 12, followed by spontaneous cyclization upon acidification, leads to the corresponding y-butyro- and -valerolactones32. 

The reaction shown in Eq. 9.47 demonstrates a short synthesis ofy-[(trityloxy)methyl]-a-alkylidene-y-butyrolactones having stereodefmed mono- and disubstituted exo-alkylidene... 

Danieli et al. 116), both of which utilize an alkylation process of 1-methyl-3,4-dihydro-(3-carboline (150) in the key ring-forming step. In the first one, treatment of 150 with a-methylene- y-butyrolactone gave enamide 172, which, when reduced with lithium aluminum hydride, afforded indolo[2,3-a]quinolizine derivative 173. The desired ethylidene substituent at C-20 has been developed from the hydroxyethyl side chain in a four-step sequence as shown below. 

SYNTHESIS OF 4-(2-BROMO-2-PROPENYL)-4-METHYL-y-BUTYROLACTONE BY THE REACTION OF ETHYL LEVULINATE WITH (2-BROMOALLYL)DIISOPROPOXYBORANE PREPARED BY HALOBORATION OF ALLENE... 

Bromo-2-propenyl)-4-methyl-y-butyrolactone 2(3H)-Furanone, 5-(2-bromo-2-propenyl)dihydro-5-methyl- (13) (138416-14-5)... 

Synthesis of 4-(2-Bromo-2-Propenyl)-4-Methyl-Y-Butyrolactone by the Reaction of Ethyl Levulinate with (2-Bromoailyl)diisopropoxyborane Prepared by Haloboration of Allene. 

DIHYDROFURAN DIVINYL ETHER METHACROLEIN 2-BUTYNE-1,4-DIOL ganna-BUTYROLACTONE cis-CROTONIC ACID trans-CROTONIC ACID METHACRYLIC ACID METHYL ACRYLATE VINYL ACETATE ACETIC ANHYDRIDE SUCCINIC ACID DIGLYCOLIC ACID MALIC ACID TARTARIC ACID n-BUTYRONITRILE ISOBUTYRONITRILE ACETONE CYANOHYDRIN... 

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