A Structure Activity Relationship (SAR) study has been used to design heterocyclic compounds such as 3 with immunosuppressive properties. a) Provide reagents, reaction conditions and a curly arrow mechanism for the synthesis of compound 3 starting from 4-oxo-pentanal 4. b) Suggest reagents and conditions A and B to synthesise 6 and 7 as shown below (no mechanisms required). B 8 c) ) Using resonance forms explain why the aldehyde functionality in compound 6 is introduced preferentially in position 2 of the pyrrole ring in compound 5. d) Briefly describe the different pharmacokinetic steps of a drug passing through the body