Question

Question: Draw the organic products formed in each reaction, and indicate the stereochemistry of the products that contain stereogenic centers.

a.

b.

c.

Short answer

Answer

a.

b.

c.

Step-by-step solution

Step-by-Step Solution Step 1: The  SN1 and SN2 reactions

Both reactions form different products. In other words, there is an inversion of the configuration that takes place in , ${\mathbf{S}}_{\mathbf{N}}\mathbf{2}$whereas${\mathbf{S}}_{\mathbf{N}}\mathbf{1}$ involves the formation of carbocation, and no inversion of the configuration takes place.

Formation of the product

a. The reaction of pentan-1-ol with ${\mathrm{PBr}}_3$undergoes the ${\mathrm{S}}_{\mathrm{N}}2$ mechanism and forms 1-chloropentane.

The reaction is shown below.

Formation of alkyl halide

b. The reaction of (R)-3-methylhexan-3-ol with HI undergoes the ${\mathrm{S}}_{\mathrm{N}}1$mechanism and forms (R)-3-iodo-3-methylhexane.

The reaction is shown below

Formation of alkyl halide

c. The reaction of (1S,2R)-2-methylcyclopentanol with ${\mathrm{PBr}}_3$undergoes the ${\mathrm{S}}_{\mathrm{N}}2$mechanism and forms the inversion of the configuration, which means that (1R,2R)-1-bromo-2-methylcyclopentane is formed.

The reaction is shown below.

Formation of alkyl halide