For the following reaction sequence, identify the expected major organic products and provide their stereochemical relationship.
A) I and II; enantiomers
B) III and IV; enantiomers
C) I and II; diastereomers
D) II and III; diastereomers
E) III and IV; diastereomers

Question

For the following reaction sequence, identify the expected major organic products and provide their stereochemical relationship.  
A) I and II; enantiomers 
B) III and IV; enantiomers 
C) I and II; diastereomers 
D) II and III; diastereomers 
E) III and IV; diastereomers

Quizplus · Accepted Answer

The first step is a Michael addition and forms a new chiral center. The major product will be (R)-1-bromo-3-methylcyclohexene (I). 
In the second step, a nucleophilic substitution occurs, and the bromine is replaced with a methoxy group. The starting material has an axial methyl group, and the product has an equatorial methyl group, resulting in two possible diastereomers. The major product will be (1R,3S)-3-methoxycyclohexene (III) and its diastereomer is (1S,3S)-3-methoxycyclohexene (IV). Therefore, the correct answer is D, II and III are diastereomers.

For the Following Reaction Sequence, Identify the Expected Major Organic