a) 6. Find the alkyl bromide(s) used in the following acetoacetic ester and malonic ester synthesis (9 points) CO₂H CO₂H OEt Alkyl haide(s)

A crossed Claisen reaction between methylpropanoate and methyl acetate is not synthetically useful because it produces a mixture of products. The reaction between methyl 2-methylpropanoate and methyl acetate, however, is synthetically useful. Explain why. 1. CH;ONa, CH3OH Mixture of products O. 2. Н,О, НСІ Methyl propanoate 1. CH3ONA, CH3OH 2. НаО, НСІ Methyl 2-methylpropanoate 78%

4. Show how the following synthesis could be performed. (7 points) OH NH

2.i) Draw the mxn for conversion of starting material A into methyl bromide and compound B upon heating at 60°C in THF for 1 day. Br A (C7H₁5BrOS) heat THF B OH + Me-Br ** What is the nucleophilic atom in the mxn's 1st step? ** What is the nucleophilic atom in the mxn's last step? ** What atom of the leaving group gains a lone pair in the mxn's last step? €

Complete the following reaction scheme. 1. DIBALH 2. H3O+ TMSCI Pyridine 1. LIAIH(t-BuO)3 SOCI2 2. H3O+ CrO3 H3O+

Rank the following species from best nucleophile to poorest nucleophile in the given solvent: но. но, A B D Nucleophilic strength in butanol: > > Best Poorest A B C|D

5. Provide an adequate route (reaction scheme) for the following reaction don

5. Draw the structure of the major organic product for each of the following reactions. H₂O, H₂SO4, HgSO4 (b) -H =H -H (d) Et =H 1. BH3, THF 2. H₂O2, NaOH, H₂O HBr (1 eq.) CH₂Cl2 HBr (excess) CH₂Cl2

What, in general, is the order of decreasing reactivity of these carbonyl compounds towards nucleophilic reagents? H H CH3CCH3 CH3C=0 (CH 3)3CCCH3 HC=0 (CH3)3CCC(CH 3)3 I II III IV V O I> III > IV> I > V O v> III >I> I| > IV O I> IV > || > II > V O IV > || >1>III > V

4. Provide a complete arrow pushing mechanism for the following reaction: H3O* ОН ОН