MS 916 - Grignard Practice

MS 916 - Grignard Practice

Textbook and Chapter: Carey and Giuliano 8th Ed. (2010), Chapter 14

Keywords: Grignard, nucleophilic acyl addition

Description: Grignard reagent problems: addition to carbonyls (aldehydes, ketones, esters), synthesis, and an NMR problem.

Total Problems: 5

  1. Problem # 668

    Show how each alcohol can be prepared from a combination of a carbonyl and a Grignard reagent.

  2. Problem # 669

    In your own words, what is the major difference in the addition of a Grignard reagent to an oxidation state III carbonyl (ester/acid chloride) versus an oxidation state II carbonyl? (aldehyde/ketone)

  3. Problem # 670

    Draw out the mechanism for the addition of excess phenyl Grignard to the carbonyl compound below.

  4. Problem # 671

    You may have noticed that the "solvent of choice" for many organometallic compounds such as Grignard reagents is ether (short for diethyl ether).

    Why is it that for Grignard reactions this solvent is used over ethyl acetate, or protic solvents such as ethanol?

  5. Problem # 672

    Compound A has molecular formula C6H12O and shows a sharp peak at 1,710 cm-1 in its IR spectrum.

    Treatment with 1 equivalent of phenyl Grignard yields compound B, which has formula C12H18O and whose IR shows a broad peak at 3,350 cm-1.

    Compound B's 1H NMR spectrum is shown below. Determine the structures of compounds A and B.