It is possible to generate sulfur ylides in a manner similar to that used to produce phosphonium ylides. For example, treating a sulfonium salt with a strong base gives the sulfur ylide. CH3 strong Ph. base CH3 Ph Br Ph CH3 `CH3 Ph A sulfonium bromide salt A sulfur ylide Sulfur ylides react with ketones to give epoxides. Suggest a mechanism for this reaction. Ph. CH3 CH `st=c CH3 CH, + Ph,S Ph

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b. A chemist wants to use a Grignard reaction to make 1-phenylethanol. Which of the following reactions will successfully form the product? Assume a final acidic workup after each. For any reactions that will not make the product correctly, propose an alternate way to get to the product. Reaction 1 Reaction 2 Reaction 3 CH3Br HBr Br Mg ether OH Mg ether Mg ether H O H r O r

A chemist has been asked to make the chemical shown below. Draw and name the one initial organic chemical used and devise a synthesis for the chemical below. Ensure you include all reagents and conditions.

Which of the following is more nucleophilic and why? CH30 (CH3)3CO 1 2 Compound 2, because its nucleophilicity is increased by the adjacent CH3 groups. Compound 2 because it is a stronger base. Compound 1, because the nucleophilicity of compound 2 is decreased by steric effects. Compound 1, because it has a weaker conjugate acid. O They actually have about the same nucleophilicity since in both, the negative charge is localized on an oxygen atom.

Propose a mechanism for the reaction of BH3 with water. The products of the first reaction are H2 gas and BH2OH. What are the products after reaction with two additional water molecules?

Propose a reasonable mechanism for the following reactions

Following is a retrosynthetic analysis for the synthesis of the herbicide (S)-Metolachlor from 2-ethyl-6-methylaniline, chloroacetic acid, acetone, and methanol. CI OMe OMe OMe 'N' HN N CI. + НО, Chloroacetic acid (S)-Metolachlor 3 NH2 CI + MEOH OMe Acetone Methanol 2-Ethyl-6-methylaniline Show reagents and experimental conditions for the synthesis of Metolachlor from these four organic starting materials. Your synthesis will most likely give a racemic mixture. The chiral catalyst used by Novartis for reduction in Step 2 gives 80% enantiomeric excess of the S enantiomer.