BackA chemist attempted the reaction below, one we introduce in Chapter 17, expecting the reaction between a strong nucleophile and a ketone in water to give an alkoxide product.
(a) Why did the reaction fail?
(b) How could the reaction conditions be changed to give a successful reaction?
Give the expected products of the following reactions. Include a protonation step where necessary.
(a) 2,2-dimethyloxirane + isopropylmagnesium bromide
(b) propylene oxide + n-butyllithium
(c) cyclopentyloxirane + ethyllithium
Fill in the boxes:
Predict the product of the diorganocuprate cross-coupling reactions shown.
(a)
Predict the product of the diorganocuprate cross-coupling reactions shown.
(b)
Based on the stereochemical result alone, how can you tell that this reaction does not proceed by an Sₙ2 mechanism?
Predict the product of the following epoxide opening reactions.
(a)
Predict the product of the following epoxide opening reactions.
(b)
A chemist failed to generate the alcohol using the reaction shown here.
(a) Suggest a reason why this reaction did not work as written.
In lieu of quenching the product of Grignard addition to a carbonyl with acid, alkyl halides can be added directly to generate ether products. Predict the product and show the mechanism of this process.
Predict the products formed when cyclohexanone reacts with the following reagents.
(f) PhMgBr and then mild H3O+
Predict the products of the following reactions.
(d) product of (c) + cyclopentylmagnesium bromide, then acidic hydrolysis
Predict the product of the following reactions.
(a)
You might expect that aldehydes and ketones could undergo the addition/elimination mechanism. With strong nucleophiles, however, nucleophilic addition is the only outcome. Why?
Beginning with an amide, two different pathways produce the same compound. Predict the product of these two pathways.