1. Introduction to Organic Chemistry Flashcards
What does achiral mean?
A molecule that is superimposable on its mirror image
What are acyclic alkanes?
alkane molecules that consist solely of chains of carbon atoms
What is an addition reaction?
A reaction in which one molecule combines with another to form a larger molecule with no other products
What is an aldehyde?
An organic compound containing the group CHO, formed by the oxidation of alcohols
What is an alkyl halide?
A group of chemical compounds derived from alkanes containing one or more halogens
What is an amide?
an organic compound containing the group —C(O)NH2, related to ammonia by replacing a hydrogen atom by an acyl group
What is an amine?
an organic compound derived from ammonia (NH3) by replacement of one or more hydrogen atoms by organic groups.
What is angle strain?
the increase in potential energy of a molecule due to bondanglesdeviating from the ideal values.
What is an arene?
aromatic hydrocarbons (most commonly based on benzene rings) such as benzene and methylbenzene.
What are axial bonds?
Bondsto non-ring atoms with angles of about 90°
What is a boat conformation?
The conformation of cyclohexane that roughly resembles a ‘boat’
What is a chair conformation?
The most stable puckered conformation of a cyclohexane ring
What does chiral mean?
Describes an object that is not superimposable on its mirror image
What is a cis isomer?
A stereoisomer in which two groups lie on the same side of a reference plane (i.e. double bond)
What are cis-trans isomers?
Stereoisomers that differ in the positioning of two groups with respect to a reference plane (i.e. double bond)
What are configurational isomers?
Isomers that cannot be interconverted by rotation around a single bond
What are constitutional isomers?
Isomers with different sequences of atom connectivity
What are cycloalkanes?
A saturated hydrocarbon with carbon atoms joined together to form a ring
What does dextrorotatory mean?
A pair of stereoisomers that are not mirror images of each other
What are diastereoisomers?
A pair of stereoisomers that are not mirror images of each other
What is an elmination reaction?
A type of organicreactionin which two substituents are removed from a molecule in either a one or two-step mechanism.
What is an enantiomer?
A pair of stereoisomers that are not superimposable mirror images of each other
What are equatorial bonds?
Bonds to non-ring atoms which make only a small angle compared with the plane of the ring
What is an ester?
A functional group generated by combining a carboxylic acid and a alcohol with the elimination of water to give a carbonyl carbon atom that is also further bound to a different saturated carbon atom via an oxygen atom linkage
What is an ether?
A compound in the form ROR, where the R groups are either alkyl or aryl groups, such that an oxygen atom is bonded to two carbon atoms that are not also bonded to a heteroatom
What is the E,Z system?
A system used to specify the configuration of groups about a carbon - carbon double bond
What is a functional group?
A group of atoms within an organic molecule that determines the molecule’s chemical reactivity
What are geometric isomers?
Each of two or more compounds that differ from each other in the arrangement of groups with respect to a double bond, ring, or other rigid structure.
What is a ketone?
A compound in which the carbon atom of the C=O group is bonded to two hydrocarbon groups
What does levorotatory mean?
Describes the anticlockwise rotation of a plane of polarised light in a polarimeter
What is optical activity?
The ability to rotate a plane of polarised light
What is oxidation?
The loss of electrons during a reaction by a molecule, atom or ion
What is a polarimeter?
A device for measuring the extent of rotation of a plane of polarised light
What is a primary carbon atom?
A carbon atom attached to only one other carbon atom
What is a racemate/racemic mixture?
A mixture of two equal amounts of two enantiomers
What is reduction?
The gain of electrons during a reaction
What is resolution?
The separation of a racemic mixture into its enantiomers
What is a secondary carbon atom?
A carbon atom attached to two other carbon atoms
What is specific rotation?
The observed rotation of a plane of polarised light when a sample is placed in a tube 1.0dm long and at a concentration of 1.0g/100mL; is a pure sample is used, its concentration is given in g/mL (i.e. its density)
What is a stereocentre?
For carbon, a tetrahedral carbon atom with four different groups bonded to it; in general terms, any atom with sufficient atoms or groups arranged around it, so that stereoisomers may be formed on exchange of any two atoms or groups
What are stereoisomers?
Isomers with the same molecular formula and the same connectivity but different orientations of their atoms in space
What is steric strain?
The strain induced in a molecule arising from the repulsion between the electrons of the bonds in the molecule
What are substituents?
A group attached to the longest carbon chain of an organic molecule
What is a substitution reaction?
A chemicalreactionduring which one functional group in a chemical compound is replaced by another functional group.
What is a tertiary carbon atom?
A carbon atom attached to three other carbon atoms
What is torsional strain?
A type of steric strain where repulsion from the electron in bonds induces a twisting force away from an eclipsing interaction
What is a trans isomer?
A stereoisomer that contains two groups that project on opposite sides of a reference plane (i.e. double bond)
How are alcohols classified as primary, secondary or tertiary?
It depends on how many carbons are attached to the carbon that the alcohol group is attached to.
1 carbon = primary
2 carbons = secondary
3 carbons = tertiary
How do you name a cycloalkane?
Prefix the names of the corresponding open-chain hydrocarbon with cyclo-, and name each substituent on the ring
What conformation does cyclopentane take?
Due to angle strain, cyclopentane forms an ‘open envelope’ structure
What conformation does cyclohexane take?
Cyclohexane forms a chair conformation
Why do geometric isomers occur?
Geometric isomers occurs due to the presence of double bonds which restricts free rotation of bonds
When the 2 top priority functional groups are on opposite sides of the carbon atom, what type of isomer is this?
Trans isomer
Using the E,Z system, if the groups of higher priority are on the same side of the double bind, what is its configuration?
Z
Using the E,Z system, if the groups of higher priority are on opposite sides of the double bind, what is its configuration?
E
What is constituent priority based on?
Priority is based on atomic number - the higher the atomic number, the higher the priority
What system is used to differentiate between two enantiomers?
The R,S System
How do you determine whether a molecule is R or S?
- Locate the steregenic center and identify each of the four substituents
- Assign priority to substituents
- Orient the lowest priority away from you
- Draw an arrow from first priority to third
If the arrow points clockwise, the molecule is R
If the arrow points anticlockwise, the molecule is S
