Valeric acid, 2-bromo-4-methyl

METHYL B-BROMOVALERATE (Valeric acid, 8-bromo-, methyl ester)... 

C) dl-Isoleucine.—One hundred and fifty grams (0.77 mole) of a-bromo-/3-methyl valeric acid is added to 645 cc. of technical ammonium hydroxide (sp. gr. 0.90) in a 1.5-I. round-bottomed flask. A stopper is wired in and the flask allowed to stand at room temperature for a week (Note 9). The stopper is removed and the mixture heated on a steam cone overnight to remove ammonia. The aqueous solution is concentrated under reduced pressure until bumping becomes violent (about 300 cc.). The mixture is then cooled to 150 and the crystals collected on a filter. The crystals are washed with 40 cc. of alcohol and dried. The filtrate is again concentrated to about 150 cc. and a second crop of crystals obtained. This second crop is washed with 25 cc. of water and then with 25 cc. of 95 per cent alcohol. The yield of crude product is 65 g. 

This is a general method for preparing a-bromo acids. By using exactly analogous directions -bromo- -caproic acid may be obtained in 65-70 per cent yields from w-butylmalonic ester a-bromo-isocaproic acid in 65-70 per cent yields from isobutylmalonic ester and a-bromo-/3-methyl valeric acid in 75-80 per cent yields from sec.-butylmalonic ester. 

Benzyl tiglate Benzyl valerate Bicycle [2.2.2]-5-octene-2-carboxylic acid, 1(or 4)-methyl-4(or 1)-(1-methylethyl) methyl ester Bicyclopentylone Bicyclopentylyl butenoate y-Bisabolene Bitter almond (Prunus amybdalus) extract L-Borneol L-Bornyl acetate Bornyl isovalerate Bromo-D-camphor B-Bromostyrene Buchu leaves oil Butanol, 2-methyl-4-(2,2,3-trimethyl-3-cyclopentenyl)- p-t-Butyl acetophenone... 

In addition, it has been shown that nucleophilic substitution reactions of mPEG-alk-oxides with ethyl 5-bromovalerate and ethyl 4-bromo-4-methyl butyrate, yield mPEG-ethyl valerate and mPEG-ethyl 2-methyl butyrate respectively, which upon hydrolysis should afford the corresponding free acids [81,82]. Presumably these reactions also give elimination products, as indicated for ethyl 3-bromopropionate. 

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