A-Bromo-y-butyrolactone

Tridecanedione, 47, 95 Triethylamine, 46,18 dehydrobromination of a-bromo-y-butyrolactone, 46, 23 dehydrobromination of o.a -dibromo-dibenzyl ketone, 47, 62 dehydrochlorination of cyclohexane-carbonyl chloride, 47, 34 in synthesis of nicotinic anhydride with phosgene, 47, 90 Triethylenetetramine, see Hexamethylenetetramine... 

A. a-Bromo-y-butyrolactone. In a 1-1., three-necked, round-bottomed flask equipped with a dropping funnel, sealed stirrer, and an efficient reflux condenser (Note 1) are placed 100 g. (1.16 moles) of redistilled 7-butyrolactone and 13.4 g. (0.43 g. atom) of red phosphorus. Over a half-hour interval, 195 g. (66.5 ml.,... 

The formation of a-bromo-y-butyrolactone has been reported in 70% yield by uncatalyzed reaction of bromine at 160-170°, as well as by the catalyzed procedure used here. ... 

Elimination of hydrogen bromide from a-bromo-y-butyrolactone with triethylamine, 46,22 Epichlorohydrin, 46, 24 Ether, /-butyl phenyl, id, 89 /j-Ethoxyphenyl isothiocyanate, 46, 21 Ethyl acetoacetate, 46, 82 Ethyl benzoyloxy cyanoacetates, 46, 38 Ethyl y-BROMOBUTYRATE, 46, 42 Ethyl 2-biomocyclopentane acetate, 46, 44... 

B. A -Butenolide. In a 500-ml. three-necked flask fitted with a mechanical stirrer, a reflux condenser, and a 250-ml. dropping funnel containing a solution of 61 g. (84.5 ml., 0.6 mole) of triethylamine in 70 ml. of dry diethyl ether, a solution of 83 g. (0.5 mole) of a-bromo-Y-butyrolactone and 200 ml. of dry diethyl ether is heated to reflux, with stirring. The amine solution is added, slowly, during 5 hours and the stirring under reflux continued for an additional 24 hours. The brown precipitate (40 g.) is removed by filtration. Most of the solvent is removed from the filtrate by evaporation, and the additional precipitate (8 g.) is removed. This precipitate is predominantly triethylamine hydrobromide. The liquid residue is distilled under reduced pressure and the -butenolide is collected at 107-109° (24 mm.) ... 

A notable exception to this rule is a-bromo-y-butyrolactone, which provides high yields of coupled products in reactions with tributylallyltin and tributylacetonyltin. J. H. Simpson and J. K. Stille, J. Org. Chem., 1985, 50, 1759. 

Price and Judge effected dehydrobromination of a-bromo-y-butyrolactone (2) to y-crotonolactone (3) by reaction with triethylamine in ether. 

Reformatsky reactions between saturated 3-ketones or 4-en-3-ones and a-bromo-y-butyrolactone afford hydroxy-lactones, e.g. (587), which dehydrate to mixtures of exo- and endo-cyclic olefins. 16-En-20-ones and, to a small extent 17-ones, also react with a-bromo-y-butyrolactone but saturated 20-ketones are unreactive. None of a series of such substituted androstane or pregnane lactones showed any significant hormonal activity. Dehydroisoandrosterone failed to undergo Reformatsky reaction with 2-bromo-6,6-dimethyl caprolactone. ... 

Bromo-4,6-dlhydro-2(3/7l-luranone a-Bromo-y-butyrolactone C4H5Br02 6061-21-2 164.986 130 1.8 1.6069 ... 

Other lactones can also be used. a-Bromo-y-butyrolactone (2.26) was converted to hydroxylactone 2.27.1 jhe lactone ring was opened by potassium phthalimide to give 2.28 and removal of the phthalimido group gave 2-hydroxy-4-aminobutanoic acid (2.29). 

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 ... 

Method Three, Livak et ad. (521). a-Bromo-y-butyrolactone (A) is prepared in 80% yield from y-butyrolactone (commercial avmlable), FBr, and bromine. a-Amino-y-hydroxybutyric acid (B) is prepared in 60% yield by amination of (A). 5-()8-Bromoethyl)-hydantoin (C) is prepared in 51% yield by the reaction of (B) with potassium cyanate to give y-hydroxy-a-ureidobutyric acid (D) and by the HBr hydrolyris of (D). 5-(j0-Methylmercaptoethyl)-hydantoin (E) is prepared in 73% yield from sodium methylmercaptide and (C). DL-Methionine is prepared in 95% yield by the Ba(OH)j hydrolysis of (E). The over-all yield is about 17%. 

Benzyl carbazate 1737 Bis(3,5-di-tert-butyl-4- a-Bromo-y-butyrolactone 1174... 

A soln. of p-phenylphenol in abs. ethanol added dropwise to a stirred soln. of 1 equivalent Na in abs. ethanol, cooled to room temp., 1 equivalent a-bromo-y-butyrolactone added dropwise with stirring, which is continued 10 hrs., then refluxed on a steam bath to neutrality a-(p-phenylphenoxy)-y-butyrolactone. Y 88%. D. T. Witiak et al., J. Med. Chem. 18, 934 (1975). 

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. 

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