Chapter08- Alkynes- An Introduction to Organic Synthesis

Chapter08- Alkynes- An Introduction to Organic Synthesis -...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Alkynes: An Introduction to Organic Synthesis Based on McMurry’s Organic Chemistry , 6 th edition, Chapter 8 ©2003 Ronald Kluger Department of Chemistry University of Toronto
Background image of page 1

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

View Full DocumentRight Arrow Icon
McMurry Organic Chemistry 6th edition Chapter 6 2 Alkynes Hydrocarbons that contain carbon-carbon triple bonds Acetylene, the simplest alkyne is produced industrially from methane and steam at high temperature Our study of alkynes provides an introduction to organic synthesis, the preparation of organic molecules from simpler organic molecules
Background image of page 2
McMurry Organic Chemistry 6th edition Chapter 6 3 8.1 Electronic Structure of Alkynes Carbon-carbon triple bond result from sp orbital on each C forming a sigma bond and unhybridized p X and p y orbitals forming a π bond The remaining sp orbitals form bonds to other atoms at 180º to C-C triple bond. The bond is shorter and stronger than single or double Breaking a π bond in acetylene (HCCH) requires 318 kJ/mole (in ethylene it is 268 kJ/mole)
Background image of page 3

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

View Full DocumentRight Arrow Icon
McMurry Organic Chemistry 6th edition Chapter 6 4 8.2 Naming Alkynes General hydrocarbon rules apply wuith “- yne as a suffix indicating an alkyne Numbering of chain with triple bond is set so that the smallest number possible include the triple bond
Background image of page 4
McMurry Organic Chemistry 6th edition Chapter 6 5 Diyines, Enynes, and Triynes A compound with two triple bonds is a diyine An enyne has a double bond and triple bond A triyne has three triple bonds Number from chain that ends nearest a double of triple bond – double bonds is preferred if both are present in the same relative position Alkynes as substituents are called “alkynyl”
Background image of page 5

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

View Full DocumentRight Arrow Icon
McMurry Organic Chemistry 6th edition Chapter 6 6 8.3 Preparation of Alkynes: Elimination Reactions of Dihalides Treatment of a 1,2 dihaloalkane with KOH or NaOH produces a two-fold elimination of HX Vicinal dihalides are available from addition of bromine or chlorine to an alkene Intermediate is a vinyl halide
Background image of page 6
McMurry Organic Chemistry 6th edition Chapter 6 7 8.4 Reactions of Alkynes: Addition of HX and X 2 Addition reactions of alkynes are similar to those of alkenes Intermediate alkene reacts further with excess reagent Regiospecificity according to Markovnikov
Background image of page 7

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

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/18/2010 for the course CHE 321 taught by Professor Fowler/sampson during the Fall '08 term at SUNY Stony Brook.

Page1 / 26

Chapter08- Alkynes- An Introduction to Organic Synthesis -...

This preview shows document pages 1 - 8. Sign up to view the full document.

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