6. Upon ozonolysis which one of the following compounds can produce acetone?
a. 3-methyl-1-butene
b. cyclopentane
c. 2-methyl-2-butene
d. 2-methyl-1-butene
The correct answer is c. 2-methyl-2-butene, as it yields acetone (propan-2-one) upon ozonolysis through cleavage of its trisubstituted double bond.[execute_python]
Ozonolysis Reaction Basics
Ozonolysis cleaves carbon-carbon double bonds in alkenes, forming carbonyl compounds (aldehydes or ketones) based on the substitution pattern at the double bond carbons. Terminal =CH2 groups yield formaldehyde (HCHO), =CHR groups yield RCHO aldehydes, and =CR2 groups yield R2C=O ketones like acetone. Reductive workup (Zn/H2O or DMS) preserves aldehydes; oxidative workup converts them to carboxylic acids.
Option Analysis
a. 3-methyl-1-butene (CH2=CHCH(CH3)CH3): The double bond is between unsubstituted CH2= and =CH- carbons, yielding HCHO + O=CHCH(CH3)CH3 (2-methylpropanal). No acetone forms.
b. cyclopentane (C5H10): This saturated cycloalkane lacks a C=C bond, so no ozonolysis occurs and no carbonyl products like acetone form.
c. 2-methyl-2-butene ((CH3)2C=CHCH3): Cleavage gives (CH3)2C=O (acetone from =C(CH3)2) + CH3CHO (acetaldehyde from =CHCH3). Acetone is produced.
d. 2-methyl-1-butene (CH2=C(CH3)CH2CH3): Yields HCHO (from CH2=) + CH3C(O)CH2CH3 (butan-2-one from =C(CH3)CH2CH3). No acetone.
