MYTUTOR SUBJECT ANSWERS

514 views

What are the stereochemical implications of bimolecular and unimolecular nucleophilic substitution?

If a chiral molecules undergoes nucleophilic substitution what happens to its stereochemistry?

SN1: These reactions occur with the production of a cationic intermediate. These contain an sphybrdised carbon atom with vacant p orbitals (hence the positive charge). The nucleophile can attack from above or below the plane of the molecule therefore producing a racemic mixture of product. If a single enantiomer is reacted with a nucleophile and the reaction proceeds via unimolecular nucleophilic substitution then equal amounts of both possible enantiomer will be formed (providing the carbon atom remains a chiral centre).

SN2: These reactions proceed via a transition state (anionic if the nucleophile is anionic) where the nucleophile attacks from one side and the leaving group leaves from the other. This results in something that resembles an umbrella turning inside out as the three unaffected groups switch sides. This means that if one enantiomer is reacted with a nucleophile then only a single enantiomer will be present in the products, although it's absolute configuration may have changed.

Henry S. A Level Chemistry tutor, A Level Biology tutor, A Level Math...

2 years ago

Answered by Henry, an A Level Chemistry tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

69 SUBJECT SPECIALISTS

£20 /hr

Ben A.

Degree: Medicine (Bachelors) - University College London University

Subjects offered: Chemistry, Physics+ 6 more

Chemistry
Physics
Maths
Biology
.UKCAT.
.BMAT (BioMedical Admissions)
-Personal Statements-
-Medical School Preparation-

“Hello,I am a first year medical student at University College London, When I was in sixth form, I helped tutor the younger years and I always enjoyed it, so I decided to keep it on in my university years.My subjects are the three m...”

£20 /hr

Laura K.

Degree: Chemical Engineering (Masters) - Bath University

Subjects offered: Chemistry, Science+ 3 more

Chemistry
Science
Physics
Maths
Further Mathematics

“Hey there! I am Laura and I am currently studying Chemical Engineering at University of Bath. I am really passionate about Science and I am willing to share my knowledge through tutoring you. My passion and expertise in science can be...”

£26 /hr

Osama H.

Degree: Medicine (MBBS/BSc) (Bachelors) - Imperial College London University

Subjects offered: Chemistry, Geography+ 4 more

Chemistry
Geography
Biology
.UKCAT.
.BMAT (BioMedical Admissions)
-Personal Statements-

“Hi I'm Osama, a medical student at Imperial College London. I'm happy to help with core subjects at GCSE, and Biology and Chemistry and A-level. I am also happy to help you get that coveted place at medical school!”

About the author

Henry S.

Currently unavailable: for regular students

Degree: Chemistry (Masters) - Durham University

Subjects offered: Chemistry, Science+ 4 more

Chemistry
Science
Maths
Extended Project Qualification
Biology
-Personal Statements-

“Durham University chemistry student here to help with A-level chemistry, biology and maths!”

You may also like...

Other A Level Chemistry questions

How do ionic charge and radius affect lattice enthalpy?

What is a chiral carbon?

What is Gibbs Free Energy?

what is a simple test to detect the presence of a carbonyl and to identify it?

View A Level Chemistry tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok