On work-up, why is the crude product (in alkaline solution) acidified and then re-basified to extract phenol, rather than by directly extracting phenol by addition of water & diethyl ether to the crude product? Your answer should include reference to the pKa values of phenol and benzoic acid.
Define the term partition coefficient, and explain why it is not necessary to calculate the partition coefficient (distribution coefficent) for the extraction in this experiment.
Experiment 2: Preparation of Cyclohexanol from Cyclohexene
List and assign the principle stretching vibrations observable in your IR spectrum of cyclohexanol
Explain in words why hydroboration leads to anti-Markovnikov addition of hydrogen whereas most electrophilic additions to alkenes result in Markovnikov addition.
Sketch the 1H NMR and 13C NMR spectra you would expect to observe for cyclohexene, assigning the signals where possible. In what ways would you expect the 13C NMR spectrum of the product (cyclohexanol) to differ from that of cyclohexene?
Experiment 3: Diels-Alder reaction of Maleic anhydride with Cyclopentadiene
The Diels-Alder reaction is usually described as a [4ps + 2ps] cycloaddition. Explain the meaning of all the terms in the square brackets.
The reaction between maleic anhydride and cyclopentadiene forms an endo-adduct (the kinetic product) at low temperatures or an exo-adduct (the thermodynamic product) at high temperatures. Explain the meaning of all the underlined terms, drawing the structures of both adducts. Sketch an energy profile for the two reactions (on the same energy plot)