How to Predict the Products with Mechanisms in a Nucleophilic Substitution versus Elimination Situation – Part 1

Nucleophilic substitution versus elimination. Go fight!


A nucleophilic substitution (SN) is a class of organic chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group (called the leaving group or LG) within another electron-deficient molecule (known as the electrophile) referred to as the substrate. This may engage either a one- (1) or two-step (2) mechanism (unimolecular and bimolecular respectively).

An elimination reaction (E) is a type of organic reaction in which two substituents are removed from a molecule in either a one- (1) or two-step (2) mechanism (unimolecular and bimolecular respectively).

Nucleophilic substitution competes with elimination. Regiochemistry and/or stereochemistry may be involved.

Question:
What are the possible products in the following reaction? Which mechanisms are likely?


Click/tap to enlarge the image

Solution infographic:



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Configurational notation (r or s) may be assigned to a pseudoasymmetric center recalling that an R substituent is above an equivalent S substituent in the CIP (Cahn-Ingold-Prelog) priority rules (the lower-case letters to be noted).

Liked the battle of chemistry ❓Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗


References:

(1)    Wikipedia Contributors. Cahn–Ingold–Prelog priority rules. Wikipedia. https://en.wikipedia.org/wiki/Cahn%E2%80%93Ingold%E2%80%93Prelog_priority_rules.

(2)    Wikipedia Contributors. Elimination reaction. Wikipedia. https://en.wikipedia.org/wiki/Elimination_reaction.

‌(3)    Wikipedia Contributors. Nucleophilic substitution. Wikipedia. https://en.wikipedia.org/wiki/Nucleophilic_substitution.‌

(4)    Chouhan, M. S. Advanced Problems in Organic Chemistry for JEE, 11th Ed.

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