Synthesis Flashcards
What happens when an organic reaction takes place
When an organic reaction takes place, bonds in the reactant molecules are broken down and bonds in the product molecules are made
What is the process bond breaking known as
The process of bond breaking is known as bond fission
What are the two types of bond fission
There are two types of bond fission homolytic and hetrolytic
Homolytic fission :
- results in the formation of two neutral radicals
- occurs when each atom retains one electron from the sigma covalent bond and the bond breaks evenly
- normally occurs when non - polar covalent bonds are broken
Why are products of homolytic fission unsuitable for organic synthesis
Reactions involving homolytic fission tend to result in the formation of very complex mixtures of products making them unsuitable for organic synthesis
Hetrolytic fission
- results in the formation of two oppositely charged ions
- occurs when one atom retains both electrons from the sigma covalent bond and the bond breaks unevenly
- normally occurs when polar covalent bonds are broken
Why are hetrolytic reactions better suited for organic synthesis
Reactions involving hetrolytic fission tend to result in far fewer products than reactions involving homolytic fission and so are better suited for organic synthesis
What does a single headed arrow indicate
- a single headed arrow indicates the moevement of a single electron
What does a double headed arrow indicate
A double headed arrow indicates the moevement of an electron pair
What does the tail of the arrow show
The tail of the arrow shows the source of the electron
What does the head of the arrow indicate
The head of the arrow indicates the destination of the electron
What do two single headed arrows starting at the middle of a covalent bond indicate
Two - single headed arrows starting at the middle of a covalent bond indicate homolytic bond fission is occuring
What does a double headed arrow starting at the middle of a covalent bond indicate
A double headed arrow starting at the middle of a covalent bond indicates hetrolytic bond fission is occuring
What does an arrow drawn with the head pointing to the space between two atoms indicate
An arrow drawn with the head pointing to the space between two atoms indicates that a covalent bond will be formed between those two atoms
How are attacking groups classifies in reactions involving heterolytic bond fission
In reactions involving heterolytic bond fission attacking groups are classified as nucleophiles or electrophiles
What are nucleophiles
Nucleophiles are negatively charged ions or neutral molecules that are electron rich, such as Cl-, Br-, CN-, NH3 and H20
What are nucleophiles attracted towards
Attracted towards atoms bearing a partial (δ+) or full positive charge
What are nucleophiles capable of
Capable of donating an electron pair to form a new covalent bond
Electrophiles are
Positively charged ions or neutral molecules that are electron deficient such as H+, NO2, and SO3
What are electrophiles attracted towards
Attracted towards atoms bearing a partial (δ-) or full negative charge
What are electrophiles capable of
Capable of accepting an electron pair to form a new covalent bond
Alkanes
- alkanes are the simplest homologous series
- alkanes contain c-c single bonds and are saturated
- the general formula is CnH2n+2
- the names of alkanes always end in ANE
Alkenes
- alkenes are another homologous series of hydrocarbons
- alkenes contain at least one c=c double bond and are unsaturated
- general formula is CnH2n
- the name of alkenes sometimes contain a number, this number indicates the position of the double bond
Types of branches
Methyl branch - one carbon atom - CH3
Ethyl branch - two carbon atoms - C2H5
Propyl branch - three carbon atoms - C3H7
If a side chain occurs more than once
di (2 branches)
tri (3 branches)
tetra (4 branches)
Branched alkane
1 - identify the longest carbon chain, name alkane with this number of carbon atoms
2 - identify branch name and name it according to the number of carbon atoms in the branch
3- number branch so it has the lowest of two possible numbers
Branched Alkenes
- position of double bond must be Identified
- number showing position placed before -ene
- the position of the double bond is more important than the position of the branch
Naming alcohols
The basic rules of naming apply: the position of the hydroxyl group is indicated before the “ol” part
General formula for carboxylic acids
Carboxylic acids
How to name carboxylic acid
The naming of carboxylic acids is similar to alkanes however the ending is replaced with “oic acid”
