For the reaction shown below (a) provide the structure of the major product (b) and a reasonable mechanism for its formation. CH3 Hg(OAc)2, H2SO4 (aq), H3C

Predict the major organic product of each of the following reactions or provide the reagent needed to complete each transformation.

2B Suggest a short synthetic route for the preparation of compound D from compound C OH Br COOH C D Note: Apart from compound C, you can also use organic reagents with up to 1 C atom. The number of arrows in the figure above does not necessarily correspond to the number of steps.

4. (A) A medicinal chemist wished to make a series of aromatic molecules bearing a ketone and thioether group with ortho, meta, or para relationships. To achieve this, they propose using nucleophilic aromatic substitution treating the corresponding ortho, meta, and para aryl chlorides with sodium ethanethiolate (NaSEt). Predict which of these reactions will likely work and which will likely fail. Provide a mechanistic explanation why. SET O NasEt EtS glagol Glal ol heat EtS target molecules EtS (B) Would the analogous reactions using EtMgBr instead of NaSEt be more or less likely to work? Explain why or why not. لمسلم EtMgBr

Paragraph 10. Answer ALL parts of this question. Treatment of acetylcyclopentane (see Scheme Q10a) with NaOEt in ethanol at 25 °C results in formation of a major, thermodynamic enolate (Scheme Q10a). NaOEt Thermodynamic enolate ELOH 25 °C (Scheme Q10a) (a) Draw the structure of the thermodynamic enolate. (b) Explain why the enolate in answer (a) is the major enolate present in the equilibrium at room temperature. (C) Draw the product formed when the thermodynamic enolate (1 mole) reacts with ethyl acrylate (1 mole) (Scheme Q10c). OEt + NaOEt Thermodynamic enolate Product ETOH 25 °C C12H2003 (Scheme Q10c) (d) Draw the kinetic product formed when 1-cyclopentene-1-carbaldehyde reacts with sodium cyanide at low temperature (5 °C) and over a short reaction time (5 minutes) (Scheme Q10d). NACN Kinetic product ELOH 5 °C (Scheme Q10d) >

3. (1) Propose each of the following syntheses (show suitable reagents for each step). OEt ماده EtO H

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(d) (i) Identify products B-F in the following reaction scheme. (ii) Provide a mechanism for the formation of B from benzene. (iii) Provide a mechanism for the formation of C from B. H2SO4 Brz B C FeBr3 Brz FeBrз H2SO4 D E & F

Answer ALL parts. (a) Treatment of enone C with tetrabutylammonium fluoride leads to the formation of heterocycle D. 2 steps BU4NF C9H1602 A + B D OSIME,tBu (i) Enone C can be prepared from alkyne A and aldehyde B in two steps via a gold-catalysed reaction. Identify A and B and provide reagents/conditions for a synthesis of C. (ii) Give the structure of D and classify the ring-closing reaction for its formation from C according to Baldwin's rules (iii) Sketch the key molecular orbitals involved in the ring-closing reaction in part (ii) and hence explain whether the reaction is favourable or unfavourable.