Lecture 19 - Chem 281 Fall 2006 Deciding between SN1, SN2,...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chem 281 Fall 2006 Deciding between S N 1, S N 2, E1, E2 1. Consider solvent and base/nucleophile. a good base/nucleophile indicates E2/S N 2 (e.g. a base/nucleophile with a negative charge) note: (CH 3 ) 3 CONa in (CH 3 ) 3 COH is still a good base even though the solvent is protic. An aprotic solvent indicates E2/S N 2 if the solvent is protic and the base/nucleophile is poor (e.g. H 2 O or (CH 3 ) 3 COH) the reaction will proceed via S N 1/E1 mechanism 2. Once you have decided whether the conditions favour E2/S N 2 or S N 1/E1 consider what type of carbon the leaving group is attached to. For E2/S N 2 conditions: 1 o (primary) carbon favors S N 2 3 o (tertiary) carbon ONLY E2 2 o (secondary) carbon – need to make a choice based on the following: - is the base/nucleophile bulky? YES rxn favors E2 NO rxn favors S N 2 3. E1/S N 1 conditions usually provide a mixture of products since the first step (RDS) is the same for both - though the more bulky the base/nucleophile the more E1 product will be formed OTHER REACTIONS COVERED (OR TO BE COVERED) *You should know all mechanistic and experimental details of these reactions that were
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/13/2011 for the course CHEM 281 taught by Professor Williams during the Spring '11 term at Simon Fraser.

Page1 / 5

Lecture 19 - Chem 281 Fall 2006 Deciding between SN1, SN2,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online