Question

Draw the SN1 mechanism of the reaction between (R)-3-methylhexane and ethanol. Show lone pairs, electron pushing arrows, 3-D view to reflect appropriate stereochemistry, reactants,intermediates, and products. name the product. draw and completely label a reaction energy diagram corresponding to the mechanism you have drawn.

B. Draw the Snl mechanism of the reaction between (R)-3-bromo-3-methylhexane and ethanol. Show lone pairs, electron pushing arrows, 3-D view to reflect appropriate stereochemistry, reactants, intermediates, and products. You do not have to show transition states. Name the product. Draw and completely label a reaction energy diagram corresponding to the mechanism you have drawn.

Answer 1

SN1 mechanism of the reaction between (R)-3-bromo-3-methylhexane and ethanol:

1. The SN1 reaction is substitution nucleophilic unimolecular reaction. The number 1 means the rate determing step as one-unimolecular. This SN1 mechanism involves two steps. The first step is the reversible ionization of (R)-3-bromo-3-methylhexane in the presence of an aqueous ethyl alcohol and second step is nucleophile (EtOH) will attack.

2.First tertiary carbocation is formed which is SP3 hybridized with trigonal planar geometry by separating the leaving group as Br^-. It is reveversible and slow step.

3. Because of this  trigonal planar geometry. of carbocation, the nucleophile (EtOH) will attack from the both side faces of carbocation which results into the product obtained is of racemic mixture of the R and S enantiomers of the product. Therefore in SN1 type reaction there would be always product obtained as racemic in nature (50% of R and 50% of S enantiomers)

4. The attached image would explain the more detail explanation on the mechanism and sterochemistry of the product formed.

5. The other image talks about the energy diagram of the SN1 reaction.

Step 1! Formation & tertiary carbocation & leaving carbocation to cart Step 2: Attack of nucleophile (Etöd) МИ Prigenal planon Cosbocation. noy osta Erol . R-Enantiomer S- Enantiom Boduts Name Racemic mixture q R&S | R-3-ethoxy-3-methyl hexane 5-3 ethexy-3-methe hoxane, a

5. The attached image talks about the energy diagram of the given SN1 reaction.

Radioan Qanate E - Smanju praxchen potenteil evage SM - un no et TSI = BB2 - atost Raamic mixture -CRIS)