Skip to main content
Ch. 12 - Substitution and Elimination: Reactions of Haloalkanes
Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
Chapter 11, Problem 55d

Predict the major product(s) of the following elimination reactions, paying close attention to the stereochemical outcome of the reactions.
(d) Chemical structure showing an elimination reaction with NaOH and H2O, focusing on stereochemical outcomes.

Verified step by step guidance
1
Step 1: Identify the type of elimination reaction. The presence of NaOH in water suggests that this is an E2 elimination reaction, which requires a strong base and occurs in a single concerted step.
Step 2: Analyze the stereochemistry of the molecule. The chlorine atom is attached to a chiral center, and elimination in E2 reactions requires the β-hydrogen to be anti-periplanar to the leaving group (Cl). This means the β-hydrogen and the chlorine must be in opposite planes for elimination to occur.
Step 3: Locate the β-hydrogens. The β-hydrogens are on the carbons adjacent to the carbon bonded to the chlorine. Examine the structure to determine which β-hydrogens are anti-periplanar to the chlorine atom.
Step 4: Predict the major product. The elimination will form a double bond between the α-carbon (the carbon bonded to the chlorine) and the β-carbon that has an anti-periplanar hydrogen. Consider Zaitsev's rule, which states that the more substituted alkene is generally the major product.
Step 5: Consider stereochemical outcomes. Since the reaction is stereospecific, the geometry of the double bond (E or Z configuration) will depend on the spatial arrangement of the substituents on the α- and β-carbons. Draw the possible products and determine the major product based on substitution and stereochemistry.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
8m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Elimination Reactions

Elimination reactions involve the removal of a small molecule from a larger one, typically resulting in the formation of a double bond. In organic chemistry, these reactions often occur with alkyl halides and can follow either E1 or E2 mechanisms. Understanding the mechanism is crucial for predicting the products, as it influences the stereochemistry and regioselectivity of the reaction.
Recommended video:
Guided course
00:40
Recognizing Elimination Reactions.

Stereochemistry

Stereochemistry refers to the spatial arrangement of atoms in molecules and how this affects their chemical behavior. In elimination reactions, the stereochemical outcome can lead to different products, such as cis or trans isomers. Recognizing the stereochemical implications of the starting material and the reaction conditions is essential for accurately predicting the major product.
Recommended video:
1:38
Polymer Stereochemistry Concept 1

Regioselectivity

Regioselectivity is the preference of a chemical reaction to yield one structural isomer over others when multiple products are possible. In elimination reactions, this often involves the formation of more stable alkenes, such as those with more substituted double bonds. Understanding the factors that influence regioselectivity, such as sterics and electronics, is key to predicting the major product in the given reaction.
Recommended video:
Guided course
05:09
Heck Reaction