CHEM 2311 Midterm: CHEM 2311 GT Examp4iia
Document Summary
Practice exam 4ii - answers: b, e, j, n, r, x, y, dd. O: h2, lindlars catalyst or ni2b; hbr, here are some descriptions of the routes: you should be able to put together the synthetic schemes. The challenge: you cannot selectively brominate adjacent to an alcohol. Retrosynthesis: you know how to make a bromohydrin from an alkene. The alkene required here is cyclohexene, which you can make from cyclohexanol. 2 steps treat the lcohol with a strog acid to promte dehydration to give cyclohexene. The challenge: to install a hydroxyl and a methoxy group trans to one another Retrosynthesis: this is tricky but you need to recognize that the product can be formed by nucleophilic ring opening of cyclohexene oxide with methoxide. 2 steps epoxiation (mcpba) of cyclohexene fgives an epoxide, which upon treatment with naoch3 give the product: base promoted double dehydrobromination of 1,2- dibromocyclohexane gives 1,3-cyclohexadiene, not cyclohexyne.
