PPT-Addition of Alcohols to Form Hemiacetals and Acetals

177 Aldehydes and ketones form hemiacetals reversibly The reaction of alcohols with aldehydes and ketones parallels the reaction with water These equilibria usually favor the starting carbonyl compound. Thiols. , Phenols, . And Ethers. IUG, . Fall . 2013. Dr. . Tarek. . Zaida. 1. 1. Alcohols. Alcohols are derivatives of hydrocarbons in which 1 or more of the hydrogen atoms has been replaced by a hydroxyl (-OH) . Dr. Talat R. Al-Ramadhany. Introduction . Aldehydes are compounds of the general formula . RCHO. ;. Ketones are compounds of the general formula . RR´CO. . The groups R and R´ may be aliphatic or aromatic. . Lecture 6. CARBONYL COMPOUNDS: . NUCLEOPHILIC ADDITION REACTION. ALDEHYDE. KETON. ESTHER. CARBOXILIC ACID. CARBONYL COMPOUNDS. CARBONYL COMPOUNDS. Formalin . Ibuprofen . Aspirin. Asam cuka. Asam semut. In General. Fragrant odors. Basic building block of housing materials. Hormones. Digestion. Vision. 2. In General. Carbonyl group. C=O. Aldehydes. RCH=O. Formyl. Ketones. RC=OR’. 3. Nomenclature. Definition. Nomenclature. Cyclic form of sugar. Optical isomerism. Glycosidic. link. Polysaccharides. Carbohydrate derivatives. Defination. Carbohydarte. are . polyhydroxy. . aldehydes,polydroxyketones. The Civet Cat is the original source of . civetone. , a sweet and pungent ketone used as a fixative in perfumery. Aldehydes and ketones are found in many fragrant odors of many fruits, fine perfumes, hormones etc. some examples are listed below.. Preparation of alkenes. Preparation of alkenes continued. Dehydration of alcohols. The H and OH are removed from adjacent carbons.. E.g. ethanol may be heated with . sulphuric. acid to create . ethene. 1. Hydration of Alkenes - . addition of water. - uses H. 2. SO. 4. and heat. Ex.; Hydrate propene.. 2. Hydrogenation of Aldehydes & Ketones –. All . carbon-carbon double bonds in the molecule will be hydrogenated at the same time. Sugar acetals are called . glycosides. .. - glycosides are stable compounds - they do not mutarotate. Figure 7.18  The structures of several important disaccharides. Note that the notation -HOH means that the configuration can be either . Division of Material. Alkenes and Alkynes are very versatile molecules in Organic Chemistry. As a result, there is a lot of information we need for them. . To make it manageable, the information is divided into two chapters.. Acetals. Maltose, a disaccharide, is produced from the hydrolysis of the starches in grains, such as barley.. In maltose, an . acetal. bond links two glucose molecules.. Learning Goal. . Draw the condensed or line-angle structural formulas for the products of the addition of alcohols to . st. 1439 . Learning. . Objectives. By the end of this chapter the student will:. . know the structure of alcohol. Knew the different classes of alcohols.. Knew the nomenclature of Alcohols . Knew the physical Properties. . Alcohols contain an OH group connected to a . a. saturated C (sp. 3. ). They are important solvents and synthesis intermediates. Phenols contain an OH group connected to a carbon in a benzene ring. Methanol, CH. Most of the alcohols are known to be . colourless. liquids or even are said to behave as solid at room temperatures. Alcohols with less molecular weight are said to be highly soluble in water; and with their increase in molecular weight, they tend to become less soluble and their .