Exam 7: Structure and Synthesis of Alkenes

A chemist has isolated a new natural product and determined its molecular formula to be C₂₄H₄₀O₄. In hydrogenation experiments the chemist found that each mole of the natural product reacted with two moles of H₂. How many rings are present in the structure of the new natural product?

Provide the major organic product in the reaction shown below.

Why is rotation about the carbon-carbon double bond in alkenes prohibited while relatively free rotation can occur about the carbon-carbon single bond in alkanes?

Provide the reagents necessary for carrying out the transformation of 2-methylheptane to 2-methylhept-1-ene

Provide the name of the major alkene product that results when (2S,3R)-2-bromo-3-methylpentane is treated with sodium methoxide in methanol.

How many elements of unsaturation are implied by the molecular formula C₅H₈O?

A newly isolated natural product was found to have the molecular formula C₁₅H₂₈O₂. By hydrogenating a sample of the compound, it was determined to possess one p bond. How many rings are present in the compound?

Which of the following statements applies to the E2 mechanism?

Which of the following cycloalkenes would be expected to be stable?

Circle the alkene isomer that has the largest heat of hydrogenation.

Provide the structure of (Z)-1-chloro-1-fluoro-1-butene.

Draw an acceptable structure for (Z)-2-chloro-4-ethylhex-2-ene.

Provide the name of the major alkene product that results when (2S,3R)-2,3-dibromopentane is treated with zinc in acetic acid.

The prostaglandin precursor arachidonic acid has the molecular formula C₂₀H₃₂O₂. Given that arachidonic acid is an acyclic carboxylic acid that contains no carbon-carbon triple bonds, how many carbon-carbon double bonds are present?

Which sequence ranks the following compounds in order of increasing heat of hydrogenation, ΔH_hyd? 1. cis-2-butene 2. 1-butene 3. cyclohexene

Alkenes ________.

Provide a correct IUPAC name for the structure below.

Using Zaitsev's rule, choose the most stable alkene among the following.

How many elements of unsaturation are implied by the molecular formula C₆H₁₂?

Provide the structure of the major organic product of the reaction below.