Concept explainers
Interpretation:
A mechanism for the formation of an acetal when α-glucose is treated with an acid catalyst is to be proposed. The structure of the stereoisomeric acetal that can be expected as a product also is to be given.
Concept introduction:
The acid will protonate one of the –OH groups in glucose. An internal nucleophilic attack of the oxygen present will eliminate water to produce an alkene. The addition of methanol to
To propose:
A mechanism for the formation of an acetal when α-glucose is treated with an acid catalyst and to give the structure of the stereoisomeric acetal that can be expected as a product.
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Chapter 19 Solutions
ORGANIC CHEMISTRY-EBOOK>I<
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- When the following compound undergoes solvolysis in ethanol, three products are obtained. Propose a mechanism to account for the formation of these products.arrow_forwardCan you draw the mechanism for the synthesis of cyclohexene from cyclohexanol through an acid-catalyzed dehydration reaction. Where Phosphoric acid donates a proton ((H^+)) to the hydroxyl group of cyclohexanol, forming a protonated cyclohexanol intermediate. • The protonated cyclohexanol undergoes dehydration, leading to the removal of a water molecule and the formation of cyclohexene. • The released proton combines with water to form hydronium ion (H3O+), regenerating the catalyst. The mechanism should illustrate the acid-catalyzed dehydration process, where phosphoric acid facilitates the removal of water from cyclohexanol, resulting in the formation of cyclohexene.arrow_forwardThe reagent diisobutylaluminum hydride (DIBALH) reduces esters to aldehydes. When nitriles are treated with DIBALH followed by mild acid hydrolysis, the product is also an aldehyde. Propose a mechanism for this reduction.arrow_forward
- The following questions concern ethyl (2-oxocyclohexane)carboxylate.(a) Write a chemical equation showing how you could prepare ethyl (2-oxocyclohexane)-carboxylate by a Dieckmann cyclization.(b) Write a chemical equation showing how you could prepare ethyl (2-oxocyclohexane)-carboxylate by acylation of a ketone.(c) Write structural formulas for the two most stable enol forms of ethyl (2-oxocyclohexane)carboxylate.(d) Write the three most stable resonance contributors to the most stable enolate derived from ethyl (2-oxocyclohexane)carboxylate.(e) Show how you could use ethyl (2-oxocyclohexane)carboxylate to prepare 2-methylcyclohexanone.(f) Give the structure of the product formed on treatment of ethyl (2-oxocyclohexane)-carboxylate with acrolein (H2C=CHCH=O) in ethanol in the presence of sodium ethoxidearrow_forwardH3C OH OH H+ CH3 Esters can be synthesized by an acid-catalyzed nucleophilic acyl substitution between an alcohol and a carboxylic acid; this process is called the Fischer esterification reaction. Because the alcohol oxygen is a poor nucleophile, the carbonyl carbon is made a better electrophile by protonation of the carbonyl oxygen. The steps of the synthesis are all reversible. The reaction is generally driven to completion by using an excess of the liquid alcohol as a solvent, or by distilling off the product as it forms. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions CIX 10-4 H₂O CH3 H₂O CH3arrow_forwardWhat reagents should be used to carry out the following syntheses?arrow_forward
- An alkene is treated with OsO4 followed by H2O2. When the resulting diol is treated with HIO4, the only product obtained is an unsubstituted cyclic ketone with molecular formula C6H10O. What is the structure of the alkene?arrow_forwardShow how 1-propanol can be converted into the following compounds by means of a sulfonate ester:arrow_forwardCyclohexene can be converted to 1-cyclopentenecarbaldehyde by the following series of reactions. СНО HIO, CH12O2 OsO, base 1-Cyclopentenecarbaldehyde Propose a structural formula for each intermediate compound.arrow_forward
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