Question detail
Which statement correctly describes the stereochemical outcome of a nucleophilic addition to a prochiral ketone?
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
MCQ
Type
practice
Style
Topic
Aldehydes and ketones (A-level only)
Question
- A. The addition always gives a single stereoisomer because the carbonyl carbon is planar.
- B. The addition gives a racemic mixture because the nucleophile can attack from either face.
- C. The addition gives a meso compound due to internal symmetry.
- D. The addition gives a single enantiomer if the nucleophile is chiral.
Answer
The addition gives a racemic mixture because the nucleophile can attack from either face.
Explanation
A prochiral ketone has a planar carbonyl carbon. A nucleophile can approach from either the Re or Si face, producing two enantiomeric alcohols. Without a chiral influence, the products are formed in equal amounts, giving a racemic mixture. This is the standard stereochemical outcome for simple nucleophilic additions to prochiral ketones.
Common mistake
Misidentifying Nucleophiles
Students often confuse nucleophiles with electrophiles, thinking that nucleophiles are positively charged species.
Remember that nucleophiles are electron-rich species that donate a pair of electrons to form a bond. They are typically negatively charged or neutral molecules with lone pairs.
Related flashcards
Flashcard 1 of 5
Related practice questions
Question 1 of 5
Choose an answer, get feedback, then move sideways through the set.