Sketch the percentage tautomeric form of Ketoacetic ester and how would you use it to synthesize 2-butanone.

here are the solutions for questions 3, 4, and 5: Question 3: a) Structures of the following compounds: (i) Cyclohexane-1,2-dione: O \\ // \\ C \\ / \\ \\ CH_2 C \\ | // \\ CH_2 O \\ / \\ \\ CH_2-CH_2 (cyclic, 6-membered ring) (ii) Cyclohexanone: O \\ // \\ C \\ / \\ \\ CH_2 CH_2 \\ | | \\ CH_2 CH_2 \\ / \\ \\ CH_2-CH_2 (cyclic, 6-membered ring) (iii) Piperitone oxide: CH_3 \\ | \\ CH \\ / \\ \\ CH_3-C CH_2 \\ // | \\ O CH_2 \\ / \\ \\ C CH \\ | / \\ CH_2-CH \\ | \\ CH_3 (cyclic, 6-membered ring with isopropyl and methyl groups, and an epoxide) (iv) Diphenol (assuming 1,2-benzenediol, catechol): C_6H_4(OH)_2 (ortho-) or OH \\ | \\ C \\ // \\ \\ HC C-OH \\ | | \\ HC CH \\ // \\ \\ C (v) 3,3-dimethylcyclohexane-1,2-dione: O \\ // \\ C \\ / \\ \\ C(CH_3)_2 C \\ | // \\ CH_2 O \\ / \\ \\ CH_2-CH_2 (cyclic, 6-membered ring) b) Two methods of preparing diols: 1. Hydroxylation of alkenes: Alkenes can be converted to vicinal diols (1,2-diols) using reagents like cold, dilute, alkaline potassium permanganate (KMnO_4) or osmium tetroxide (OsO_4) followed by reduction. Equation (using KMnO_4): RCH=CHR' + KMnO_4 (cold, dilute, alkaline) RCH(OH)CH(OH)R' 2. Hydrolysis of epoxides: Epoxides (oxiranes) can be hydrolyzed under acidic or basic conditions to yield vicinal diols. Equation (acid-catalyzed hydrolysis): RCH \\ / \\ O \\ \\ \\ CHR' + H_2O H^+ RCH(OH)CH(OH)R' c) Structures of the following compounds: (i) Propane-1,3-dial (malonaldehyde): OHC-CH_2-CHO (ii) 1,3-Diphenyl-1,3-dione (assuming 1,3-diphenylpropane-1,3-dione, dibenzoylmethane): C_6H_5COCH_2COC_6H_5 (iii) Pentane-2,4-dione (acetylacetone): CH_3COCH_2COCH_3 (iv) Heptane-2,5-dione: CH_3COCH_2CH_2CH_2COCH_3 (v) 2,5-Hexanedione (assuming "2,5-phenyl dione" is a typo for 2,5-hexanedione, a common -diketone): CH_3COCH_2CH_2COCH_3 Question 4: a) Structures of glycol dinitrate and glyceryl trinitrate: • Glycol dinitrate (ethylene glycol dinitrate): O_2NOCH_2CH_2ONO_2 • Glyceryl trinitrate (nitroglycerin): O_2NOCH_2CH(ONO_2)CH_2ONO_2 Three properties of these compounds: • They are explosive due to the presence of multiple nitrate groups. • They are highly unstable and sensitive to shock and heat. • They are powerful vasodilators and are used in medicine (e.g., nitroglycerin for angina). b) Three properties of polyols: • They have high boiling points due to extensive intermolecular hydrogen bonding. • They are typically viscous liquids at room temperature. • They are highly soluble in water due to the presence of multiple hydroxyl groups. c) Structure of the simplest triol and reason for elevated boiling point: The simplest triol is glycerol (propane-1,2,3-triol). HOCH_2CH(OH)CH_2OH Glycerol has an elevated boiling point (290 °C) because it contains three hydroxyl (-OH) groups. These hydroxyl groups allow for extensive intermolecular hydrogen bonding between glycerol molecules. Hydrogen bonds are strong intermolecular forces that require a significant amount of energy to overcome, leading to a higher boiling point compared to compounds of similar molecular weight but fewer hydroxyl groups. Question 5: a) Definition of protein: A protein is a large, complex biomolecule composed of one or more long chains of amino acid residues. These chains are linked together by peptide bonds and fold into specific three-dimensional structures essential for their biological function. b) Six examples of body materials where proteins are important constituents: • Enzymes (e.g., amylase, pepsin) • Hormones (e.g., insulin, growth hormone) • Antibodies (immunoglobulins) • Structural components (e.g., collagen in connective tissue, keratin in hair/nails) • Transport proteins (e.g., hemoglobin for oxygen transport) • Muscle fibers (e.g., actin and myosin for muscle contraction) c) Six biological importance of protein to the human system: • Catalysis: Enzymes, which are proteins, catalyze nearly all biochemical reactions in the body. • Structural Support: Proteins like collagen and keratin provide structural integrity to tissues, organs, hair, and skin. • Transport: Proteins such as hemoglobin transport oxygen, while others transport nutrients, ions, and waste products. • Immunity: Antibodies (immunoglobulins) are proteins that identify and neutralize foreign invaders like bacteria and viruses. • Movement: Actin and myosin are proteins responsible for muscle contraction and cellular movement. • Regulation: Many hormones (e.g., insulin) are proteins that regulate various physiological processes, and receptor proteins mediate cell signaling. What's next? Send 'em!