Alcohols reactions with base

Reaction with base brings the alcohol function of the halohydrin into equilibrium with Its corresponding alkoxide... 

Commercial alkylphenol ethoxylates are almost always produced by base-cataly2ed ethoxylation of alkylphenols. Because phenols are more strongly acidic than alcohols, reaction with ethylene oxide to form the monoadduct is faster. The product, therefore, does not contain unreacted phenol. Thus, the distribution of individual ethoxylates in the commercial mixture is narrower, and alkylphenol ethoxylates are more soluble in water. 

Cyclohexadienol was prepared by Rickborn in 1970 from reaction of the epoxide of 1,4-cyclohexadiene with methyl lithium.100 A hydrate of naphthalene, 1-hydroxy-1,2-dihydro-naphthalene was prepared by Bamberger in 1895 by allylic bromination of O-acylated tetralol (1-hydroxy-l,2,3,4-tetrahydronaphthalene) followed by reaction with base.101 Hydrates of naphthalene and other polycylic aromatics are also available from oxidative fermentation of dihydroaromatic molecules, which occurs particularly efficiently with a mutant strain (UV4) of Pseudomonas putida.102,103 The hydrates are alcohols and they undergo acid-catalyzed dehydration to form the aromatic molecule by the same mechanism as other alcohols, except that the thermodynamic driving force provided by the aromatic product makes deprotonation of the carbocation (arenonium ion) a fast reaction, so that in contrast to simple alcohols, formation of the carbocation is rate-determining (Scheme 6).104,105... 

Several reaction intermediates can be observed by varying the reaction conditions. If equimolar amounts ofbromine and hydroxide are added to acetamide (26, R = Me, Scheme 2.11), the product is N -bromoacetamide (27, R = Me). Further reaction with base gives unstable salts (28), which rearrange to isocyanates (29) reaction with water and an excess of hydroxide finally leads to the amine product (30), but in alcoholic solutions urethanes (31) are formed. 

Reacts with water or steam to produce heat. Violent reaction with bases (e.g., sodium hydroxide, potassium hydroxide, calcium hydroxide), alkali metals (e.g., sodium, potassium), amines (e.g., dimethylamine, triethylamine), lithium, pyridine. To fight fire, use alcohol foam. Incompatible with cations. When heated to decomposition (above 150°C) it emits acrid smoke and irritating fumes. See also ANHYDRIDES. 

The main reactions studied have been oxidation to the corresponding acids, reduction to the corresponding polyhydric alcohol, or partial reduction to an intermediate aldehyde-alcohol reaction with nitrogenous bases has been studied, and also the reaction of the products with alkylating and acylating reagents. Many of the oxidation products are extremely labile to alkali, and this has been a wide field of study, particularly with the oxidation products from polysaccharides. The oxidation products will be divided into classes, and dealt with compound by compound, except for the reaction with alkali, which will be discussed separately. 

The base-catalyzed reaction in Equations (2a) and (2b) is very similar to the corresponding alcohol reaction with this difference. Since the mer-captide ion is more nucleophilic than the alkoxide ion one will expect that smaller differences in the charge density around the carbonyl carbon of the isocyanate will affect the reactivity of the mercaptides than that of the alkoxides. This would explain the higher sensitivity of thiols to base-catalysis and the higher activity of bases for the catalysis of the thiol reaction. 

ANTIMONOUS BROMIDE (7789-61-9) BfjSb Decomposed by light, air, and alcohol. Contact with moist air, water, steam, or alcohol produces corrosive hydrobromic acid and antimony trioxide. The aqueous solution is and acid. Violent reaction with bases, amines, amides, and inorganic hydroxides potassium, sodium. On small fires, use dry chemical powder (such as Purple-K-Powder), dry sand, or CO2 extinguishers. 

Violent reaction with bases, oxidizers, organic materials, phenyl azide, sihcon tetrahydride. Contact with alcohols, alkyl nitrates, amines, ethylene oxide, potassium, sodium, turpentine may cause fire and explosions. Contact with ethylene oxide may cause violent polymerization. Inconq>atible with glycidol, Attacks some plastics, rubber, and coatings. Conosive to metals, especially in the presence of moisture. On small fires, use dry chemical powder (such as Piuple-K-Powder), sand, or CO extinguishers. 

---