The analgesic, soporific, and euphoriant properties of the dried juice obtained from unripe seed pods of the opium poppy Papaver somniferum have been known for centuries. By the beginning of the nineteenth century, the active principle, morphine, had been isolated and its structure determined. Even though morphine is one of modern medicine's most effective painkillers, it has two serious disadvantages. First, it is addictive. Second, it depresses the respiratory control center of the central nervous system. Large doses of morphine (or heroin, which is the 3,6-diacetyl ester of morphine) can lead to death by respiratory failure. Me. H Me. OH MeO Morphine Morphinan (+/-) = Racemethorphan (+) = Dextromethorphan (-) = Levomethorphan %3D %3D For these reasons, chemists have sought to produce painkillers related in structure to morphine, but without the serious disadvantages. One strategy has been to mod- ify the carbon-nitrogen skeleton of morphine in the hope of producing medications equally effective but with reduced side effects. One target of this synthetic effort was morphinan, the bare morphine skeleton. Among the compounds thus synthe- sized, racemethorphan (the racemic mixture) and levomethorphan (the levorotatory enantiomer) proved to be very potent analgesics. Interestingly, the dextrorotatory enantiomer, dextromethorphan, has no analgesic activity. It does, however, show approximately the same antitussive (cough-suppressing) activity as morphine and is therefore used extensively in cough remedies. Following is a synthesis of racemethorphan. H NC H,N- H,PO, Meo (A) (B) (C) H NaBH, (redraw) H,PO, MeO MeO MeO (D) (E) H,C EtO MeO MeO MeO (F) (G) Racemethorphan

Which of the following is a substrate product when benzene is first treated with Cl2 and FeCl3, and THEN treated (in a second step) with HNO3 and H2SO4?

Draw the major organic product from the reaction sequence provided: Select Draw Rings More // Cl C 1. SOCI2 2. Et,CuLi 3. (a) LIAIH4 (b) H2O OH

1. Polyketide synthesis (PKS) is a process by which many natural products such as macrolide antibiotics (e.g., erythromycin) are made. An important part of this process is the reduction of formed ketones to alcohols using a domain known as a keto-reductase. Keto-reductase catalyzes the delivery of hydride from NAD(P)H to the ketone. Provide a logical reaction mechanism using the arrow formalism. Enz Enz S S H H H „R Keto Reductase .R OH H, OH OH ŅH2 CH3 0oC. + NH3 ОН ОН