(b)
5. All of the following names are incorrect or incomplete. In each case, draw the structure (or a possible structure) and name it correctly.
$$
(2 \text { pts) }
$$
(a) 2-ethyl-3-methylpentane
(b) 3-bromo-5-methylhexane
6. Suggest the major organic product(s) for each of the following reactions: (3 pts)
a)
(cd)
$$
\leftrightarrow
$$
(d)
4. Give the IUPAC name for: (2pts)
(a)

Question

Accepted Answer

∻Solution∻ ‖ 1 ⋮ **Identify the incorrect name**: The name "2-ethyl-3-methylpentane" suggests a pentane chain with an ethyl and a methyl substituent. However, this is not possible as the longest carbon chain can only have five carbons, and with substituents at positions 2 and 3, there would be no room for an ethyl group (which requires two carbons). ‖ ‖ 2 ⋮ **Correct the structure and name**: The correct structure would have the longest carbon chain possible, which is hexane in this case, with methyl and ethyl substituents. The correct IUPAC name is "3-ethyl-2-methylhexane". ‖ ‖ 3 ⋮ **Identify the incorrect name**: The name "3-bromo-5-methylhexane" suggests a hexane chain with a bromo substituent at position 3 and a methyl substituent at position 5. This name is incorrect because numbering should minimize the positions of the substituents. ‖ ‖ 4 ⋮ **Correct the structure and name**: The correct IUPAC name should be "3-bromo-2-methylhexane" to reflect the lowest possible numbers for the substituents. ‖ ‖ 5 ⋮ **Identify the reaction**: The reaction given is a hydroboration-oxidation reaction, which converts alkenes to alcohols. ‖ ‖ 6 ⋮ **Predict the major product**: The major product of the reaction between "CH3" (which is likely a shorthand for an alkene with a methyl group) and "1. BH3, 2. NaOH, H2O2" would be an alcohol. The boron from BH3 adds to the less substituted carbon of the double bond, and subsequent oxidation with NaOH/H2O2 replaces the boron with a hydroxyl group. ‖ ‖ 7 ⋮ **Determine the IUPAC name**: Without the structure provided for question 4, it is not possible to give the IUPAC name. ‖ ∻5 Answer∻ ⚹ 3-ethyl-2-methylhexane ⚹ ∻6 Answer∻ ⚹ The major product is an alcohol with the hydroxyl group on the less substituted carbon of the original double bond. ⚹ ∻Key Concept∻ ⚹ Correcting incorrect or incomplete chemical names involves ensuring the longest carbon chain is identified and substituents are named with the lowest possible numbers. Hydroboration-oxidation reactions convert alkenes to alcohols with anti-Markovnikov regioselectivity. ⚹ ∻Explanation∻ ⚹ For question 5, the names were corrected by identifying the longest carbon chain and assigning the lowest possible numbers to the substituents. For question 6, the major product was determined based on the regioselectivity of the hydroboration-oxidation reaction. ⚹◊What is the IUPAC name for 3-bromo-5-methylhexane?⍭ Generate me a similar question◊

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