Description: Enolate formation and carbonyl alpha position pKa.
Aldol and Claisen condensations.
Total Problems: 8
Rank each group of acids in order of decreasing acidity. (1 = most acidic)
Explain your reasoning. You will have to use more than one rule in your explanation (resonance, electronegativity, atomic radius, etc.).
After a sample of optically pure (S)-2-ethyl-cyclohexanone is dissolved in an aqueous solution for several hours, a significant loss of optical activity is observed. Explain.
The molecule below has five different types of hydrogens (A through E). Rank each in order of decreasing acidity.
(1 = most acidic). Explain your reasoning.
Show what combination of aldehyde, ketone, and/or ester can prepare each compound below. Every compound is a Claisen or aldol product.
Show a combination of enolate (nucleophile) and electrophile that can produce each compound below.
Remember that all enolates come from carbonyls.
Alpha bromination is usually carried out under acidic conditions via the enol intermediate.
Alpha bromination is uncontrollable under basic conditions, which goes through the enolate intermediate. Let's explore why.
a) Rank each carbonyl below in order of decreasing alpha-proton acidity (1= most acidic). Explain.
b) based on a), why does the reaction below lead to polyhalogenation?
Show how to prepare each compound below from propanal. I've marked the "cuts" for you.
Let's work through a Robinson annulation.
Work backwords to determine the starting materials needed to produce each intermediate below, then show a mechanism for the overall reaction.