Question 3 [TOTAL WEIGHT: 40% TOTAL MARKS: 100] 3(a) [20 Marks] Illustrate the complete mechanism for the Aldol condensation reaction between one molecule of acetone (CH3COCH3) with two molecules of benzaldehyde (C&HCHO) in the presence of NaOC2Hs; your mechanism should include illustrating the effect of the NaOC2H5 and the structure of the final product. 3(b) [40 Marks] For the reaction shown below illustrate the nucleophilic substitution mechanism that occurs showing all the steps involved: (CH3)3CBr + CH OH Include the structure of the major organic product formed. Explain if the mechanism is via SN1 or SN2: justify your choice by identifying and referring to the type of() substrate (ii) nucleophile (ii) leaving group for this reaction. By replacing the nucleophile in the above reaction with a base such as LDA, an alternative reaction can occur providing a different organic product. Outline the mechanism for this reaction (naming this reaction type) and include the name and structure of the organic product formed