Chapter 19, Problem 45PP

Shown are two stereo representations of lactic acid. Compare the two structures shown. Determine whether they represent identical molecules or mirror images. identical COOH COOH H" OH CH3 H3C HO Determine the absolute configuration of the two structures. Left: S✔ Right: S An error has been detected in your answer. Check for typos, miscalculations etc. before submitting your answer. H

Draw a structural formula of the S configuration of the compound shown below. • Use the wedge /hash bond tools to indicate stereochemistry where it exists. Include H atoms at chiral centers only. • Ifa group is achiral, do not use wedged or hashed bonds on it. CH3 CH3 CH;CHCHCN CH,CH,CH,CHCH,CH, CH2NH2 Draw a structural formula of the RS configuration of the compound shown below. Use the wedge /hash bond tools to indicate stereochemistry where it exists. • Include H atoms at chiral centers only. If a group is achiral, do not use wedged or hashed bonds on it. ÇI

Examine the reaction below, and answer the question in the box. If the reaction is possible, draw the simplest possible mechanism for it, showing all lone pairs. You may need to expand parts of the structures to show some lone pairs. If the reaction is not possible, leave the drawing space blank. Is this reaction possible? You can assume that all reactants and products are shown. H OH + O yes O no

1. Tell whether the following pairs of structures are identical or not. 2. For those pairs that are not identical, explain what types of isomers they are. 3. If there are chiral centers, denote them with the correct R,S.

e) H₂CN نده بده بله Br. NH 1. (CH3)₂CHMgBr, ether 2. NH,C1, H,O Products نده ده Br. NH H H له H

Circle all of the chiral centers (i.e., asymmetric carbon atoms) in the following compounds.

(i) Name the compound below. H H, H (ii) Draw the most stable Newman projection looking down the C2-C3 bond. HO, 3 (iii) Draw the lowest energy conformer for the following compound.

3: Draw bond-line structures (with wedges or dashes, where appropriate) of each of the following molecules. Be sure to draw the correct stereoisomer of any chiral molecules. a: H. H I I C: H. OH b: CH3 H S CH3 H Br CH3 CH3 CI CH3

Tall 1,2-dichlorocy 3. The structure below is Formeterol, a long-acting b-adrenergic agonist (LABA) used in combination with inhaled steroids for maintenance therapy in asthma and other respiratory disorders. O H OH H N HO Redraw the structure, and label all functional groups by name. H