Chapter 7 Flashcards
An old classification for a compound that is an alkene, stemming from “oil-forming gas”
Olefin
Diastereomers that differ in their stereochemistry at adjacent atoms of a double bond or on different atoms of a ring; cis = same side and trans = opposite sides
Cis-trans isomers
A system for designating the stereochemistry of alkene diastereomers based on the properties of groups in the Cahn-Ingold-Prelog convention. An E isomer has the highest priority groups on opposite sides of the double bond, a Z isomer has the highest priority groups on the same side of the double bond
(E)-(Z) system
A reaction in which hydrogen adds to a double or triple bond; is often accomplished through the use of a metal catalyst, such as platinum, palladium, rhodium, or ruthenium
Hydrogenation
The standard enthlapy change that accompanies the hydrogenation of 1 mol of a compound to form a particular product
Heat of hydrogenation
A reaction that results in the loss of two groups from the substrate and the formation of a π bond. The most common elimination reaction is a 1,2 elimination or β elimination, in which two groups are lost from adjacent atoms
Elimination reaction
An elimination reaction that results in the loss of HX from adjacent carbons of the substrate and the formation of a π bond
Dehydrohalogenation
A bimolecular 1,2 elimination in which, in a single step, a base removes a proton and a leaving group departs from the substrate, resulting in the formation of a π bond
E2 reaction
A unimolecular elimination in which, a slow, rate-determining step, a leaving group departs from the substrate to form a carbocation. The carbocation then, in a fast step, loses a proton with the resulting formation of a π bond
E1 reaction
A rule stating that an elimination will give as the major product the most stable alkene (i.e., the alkene with the most highly substituted double bond)
Zaitsev’s rule
A principle stating that when the ratio of products of a reaction is determined by relative rates of a reaction, the most abundant product will be the one that is formed the fastest
Kinetic (or rate) control
When an elimination yields the alkene with the less substituted double bond
Hofmann rule
A confirmation in which Vicinal groups lie in the same plane
Coplanar
The relative position of two groups that have a 180* dihedral angle between them
Anti coplanar
The relative position of two groups that have a 0* dihedral angle between them
Syn coplanar
An elimination that involves the loss of a molecule of water from the substrate
Dehydration
A reaction that results in a product with the same atoms present but a different carbon skeleton from the reactants. A 1,2 shift is a rearrangement that involves the migration of a group (with its electrons) from one atom to the atom next to it
Rearrangement
A methyl anion, -:CH3, or methyl species that reacts as though it were a methyl anion
Methanide
The migration of a chemical bond with its attached group from one atom to an adjacent atom
1,2 shift
An alkyl anion, R:-, or alkyl species that reacts as though it were an alkyl anion
Alkanide
A hydrogen anion, H:-, or a species that reacts as though it were a hydride anion. Hydrogen with a filled 1s shell (containing two electrons) and negative charge
Hydride
A hydrogen atom attached to a carbon atom that is bonded to another carbon atom by a triple bond
Acetylenic hydrogen atom
A general term for a molecule having halogen atoms bonded to each of two adjacent carbons
Vicinal dihalides (vic-dihalide)
When two identical groups are bonded to the same carbon
Geminal
A general term for a molecule or group containing two halogen atoms bonded to the same carbon
Geminal dihalide (gem-dihalide)
The introduction of an alkyl group into a molecule
Alkylation
Catalytic reaction in which the catalyst is insoluble in the reaction mixture
Heterogeneous catalysis
Catalytic reactions in which the catalyst is soluble in the reaction mixture
Homogeneous catalysis
A compound that doesn’t contain any multiple bonds
Saturated compound
A compound that contains one or more double bonds
Unsaturated compound
An addition that places both parts of the adding reagent on the same face of the reactant
Syn addition
An addition that places the parts of the adding reagent on opposite faces of the reactant
Anti addition
Metallic palladium deposited on calcium carbonate
Lindlar’s catalyst
A method for planning syntheses that involves reasoning backward from the target molecule through various levels of precursors and thus finally to the starting materials
Retrosynthetic analysis
