3.a. Identify molecules B through E in the sequence below, and show the mechanisms of their formation. Be sure to include stereochemistry where applicable. You do not need to draw

chairs. (8 marks) b. The SN2 reaction can occur intramolecularly i.e. within the same molecule. Draw the expected product, with a mechanism, when the molecule below is treated with a base like sodium hydride, NaH in DMF solvent. Make sure to include stereochemistry where applicable. (4 marks) c. With your answer to part (d) in mind, suggest a synthesis,with mechanisms shown, for the molecule below. (4 marks) (Consider carefully: on which carbon you want your nucleophile and leaving group to be?) Circle all chirality centre(s) and assign R or S configuration(s)to them. (2 marks) Can you predict a numerical value for the optical rotation of the compound? Why? (2 marks)ChemicPBr3 P d. You were instructed to synthesize 1,4-dioxane. Looking around the lab, you find only ethylene glycol, phosphorus tribromide, sodium hydroxide, sodium hydride and DMF solvent. Propose a synthesis of 1,4-dioxane using only the chemicals you found. Include reaction conditions like reagents, solvent etc. Mechanisms are not required.Assume you have an unlimited supply of the chemicals. (8marks)