19. Cocaine Biosynthesis (20 pt) Cocainc is isolated from the leaves of Erythoxylum coca (coca plants). Although the exact biosynthetic pathway leading to cocaine has not been fully established, one current hypothesis is that it includes the following enzyme-catalyzed reactions. 1 A. Draw a curved arrow mechanism for the following reaction, using an iminium as the first electrophile. EnzB (cat.) HSCOA SCOA (2 equiv) ON / SCOA Η B. Classify the following reaction. [ 0 0 O oxidation O reduction : SCOA ON ΤΗ ——- ON SCOA C. Draw a curved arrow mechanism for the following reaction. Add stercochemistry (wedged/dashed lines) to the starting structure based on the stereochemistry of the product structure. OSCOA EnzB (cat.) ON SCOA (add stereochemistry)