Chapter 5.5, Problem 20ATS

Draw a structural formula for the substitution product of the reaction shown below. +- Na SCH3 CH3CN • Use the wedge/hash bond tools to indicate stereochemistry where it exists. If more than one stereoisomer of product is formed, draw both. ● Separate multiple products using the + sign from the drop-down menu. • Products that are initially formed as ions should be drawn in their neutral forms.

Draw the structure(s) of the major organic product(s) of the following reaction. 1 eq. Br2 Aqueous K2CO3 0 • Use the wedge/hash bond tools to indicate stereochemistry where it exists. If the reaction produces a racemic mixture, draw both stereoisomers. If no reaction occurs, draw the organic starting material. • Draw one structure per sketcher. Add additional sketchers using the drop-down menu in the bottom right corner. Separate multiple products using the + sign from the drop-down menu. • 424 On []

The shrub ma huang (Section 5.4A) contains two biologically active stereoisomers—ephedrine and pseudoephedrine—with two stereogenic centers as shown in the given structure. Ephedrine is one component of a once-popular combination drug used by body builders to increase energy and alertness, whereas pseudoephedrine is a nasal decongestant. a.Draw the structure of naturally occurring (−)-ephedrine, which has the 1R,2S configuration. b.Draw the structure of naturally occurring (+)-pseudoephedrine, which has the 1S,2S configuration. c.How are ephedrine and pseudoephedrine related? d.Draw all other stereoisomers of (−)-ephedrine and (+)pseudoephedrine, and give the R,S designation for all stereogenic centers. e.How is each compound drawn in part (d) related to (−)-ephedrine?