Under certain reaction conditions, 2,3-dibromobutane reacts with two equivalents of base to give three products, each of which contains two new

$$\pi$$

bonds. Product A has two sp hybridized carbon atoms, product B has one sp hybridized carbon atom, and product C has none. What are the structures of A, B, and C?

Draw the major product formed when (3R)-1-chloro-3-methylpentane is treated with each reagent:

$$\text { (a) } \mathrm { NaOCH } _ { 2 } \mathrm { CH } _ { 3 } ; ( \mathrm { b } ) \mathrm { KCN }; \mathrm {(c)} \mathrm { DBU.}$$

Identify the stronger nucleophile in each pair of anions.

$$a. \mathrm { Br } ^ { - } \text { or } \mathrm { Cl } ^ { - }$$

in a polar protic solvent.

$$b. \mathrm { HO } ^ { - } \text { or } \mathrm { Cl } ^ { - }$$

in a polar aprotic solvent.

$$\mathrm { c. } \mathrm { HS } ^ { - } \text { or } \mathrm { F}^ { - }$$

in a polar protic solvent.

Label each pair of alkenes as constitutional isomers or stereoisomers.

Classify each solvent as protic or aprotic.

$$\begin{array} { l } { \text {a. } \left( \mathrm { CH } _ { 3 } \right) _ { 2 } \mathrm { CHOH } } \\ { \mathrm { b } . \mathrm { CH } _ { 3 } \mathrm { NO } _ { 2 } } \end{array} \quad \begin{array} { l l } { \mathrm { c. } } & { \mathrm { CH } _ { 2 } \mathrm { Cl } _ { 2 } } \\ { \mathrm { d } . } & { \mathrm { NH } _ { 3 } } \end{array}\quad \begin{array} { l } { \text { e. } \mathrm { N } \left( \mathrm { CH } _ { 3 } \right) _ { 3 } } \\ { \text { f. HCONH} _ {2 } } \end{array}$$