Dibromohydrins

The dibromohydrin is a heavy, colorless liquid with a characteristic odor. On standing it gradually becomes yellow. Its specific gravity at 20° is about 2.14. 

The crude dibromohydrin distils without any decomposition at 10-15 pressure if the temperature of the oil bath is not raised over 190°. Above this temperature formation of acrolein derivatives begins, which, even if present in very small amounts, makes the dibromohydrin lachrymatory. 

Glycerol a,7-dibromohydrin has been prepared from glycerol and phosphorus tribromide from glycerol and bromine from glycerol, red phosphorus, and bromine. ... 

B) Epibromohydrin.—In a 5-I. round-bottomed flask, 2140 g. (1000 cc., 9.8 moles) of glycerol a ,t-dibromohydrin (Org. Syn. 14, 42) is suspended in 1.5 1. of water, and 400 g. of technical, powdered calcium hydroxide (88 per cent) is added gradually, with shaking, in the course of about fifteen minutes. A further quantity of 400 g. of calcium hydroxide (total, 10 moles) is added at once, and the epibromohydrin is distilled at reduced pressure in the manner described for epichlorohydrin (Note 2). The combined lower layers from two such distillations (about 750 cc.) are dried over anhydrous sodium sulfate and fractionated at atmospheric or reduced pressxue. The yield of epibromohydrin, b.p. 134-136° or 6i-62°/5o mm., is 1130-1200 g. (84-89 per cent of the theoretical amount). 

Epichlorohydrin 1 and epibromohydrin have been prepared by treatment of glycerol dichloro- and dibromohydrins with... 

In the case of the oxidation of glycerol, D,L-glyceric acid has also been isolated. Hlasiwetz and Habermann treated glycerol with chlorine water and obtained the acid as the main product. From the action of bromine water on glycerol, Barth obtained glyceric acid, bromoform and carbon dioxide. In the absence of water, bromine converted glycerol to dibromohydrin and bromoacetic acid. The former decomposed to hydrogen bromide and acrolein. 

A dibromohydrin of pentaerythritol (LX) was synthesized according to Zelinsky and Krawetz and, on being subjected to permanganate oxidation, gave as the product 2,2-bis(bromomethyl)-3-hydroxypropanoic acid (LXI). Attempts at further oxidation led only to the complete destruction of the compound. A diethyl ether of pentaerythritol was also made from the cor-... 

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