As ____________ increases boiling and melting point increase
As ____________ increases boiling point decreases and melting point increases
Combustion of alkanes
When oxygen is added to an alkane at high temperatures, the products produced are CO2, H2O, and heat
One or more hydrogen replaced with halogen. Initiation, propagation and termination. The more stable the intermediate is, the more likely the reaction is to occur. 3>2>1>methyl. Therefore, tertiary free radical is most likely formed and most is formed during propagation, not during termination.
The ________ substituted the alkene, the more thermodynamically stable.
Dehydration of an alcohol
An E1 reaction where an alcohol forms an alkene in the presence of hot concentrated acid.
A general reaction type in which a saturated reactant yields an unsaturated product by losing groups from two adjacent carbons
Same trend as radical stability, 3° > 2° > 1° > methyl. Rearrangement will only occur if a more stable carbocation (C+) can be formed.
States that the major product of elimination will be the most substituted alkene
E1 - Weak Base -- Two steps (1. Halo leaves and proton is removed by base)
E2 - Strong Bulky base -- One step (proton is removed and halogen is dropped simultaneously). Bulky base prevents SN2, but if too bulky, no saytzeff and least substituted alkene is produced
Reducing an alkene by adding molecular hydrogen to double bond with aid of metal catalyst. e.g. pt, pd, ni. takes place on surface of metal so it does syn addition
Oxidation of alkenes
May produce glycols (hydroxyl groups on adjacent carbons) or may cleave teh alkene at the double bond as in ozonolysis. Alkynes produce carboxylic acids when undergoing ozonolysis
An atom (or group of atoms) that is attracted to an electron-rich centre or atom, where it accepts a pair of electrons to form a new covalent bond.
Hydrogen will add ot the least subtitued carbon on the double bond in electrophilic addition
In the presence of peroxides ROOR, the halogen will add to the least substituted carbon.
Hydration of an alkene
Hydration takes place when water is added to an alkene in the presence of an acid. This is the reverse of dehydration of an alcohol
Creates an alcohol from an alkene. Markovnikov, anti addition, no carbocation rearrangement
Produces an alcohol from an alkene. Anti-Markovnikov addition, syn addition, replacement of BR2 with other functionalities, quasicyclic intermediate
Halogenation of an alkene
Br₂ and Cl₂ add to alkenes readily via anti-addition to form vic-dihalides (two halogens connected to adjacent carbons).
A compound containing a halogen atom and a hydroxyl group on adjacent carbons;
A reaction that occurs when one functional group replaces another.
1. Ionization to form a carbocation, this is the rate-determining step. 2. The reaction of the carbocation with a nucleophile. Favored in polar protic solvents; Most stable 3º>2º>1º>methyl; rate=k[RX]; Racemic products; Favored with the use of bulky nucleophiles
1 step reaction; Favored in polar aprotic solvents; Most stable 1º>2º>3º; rate=k[Nu][RX]; Optically active/inversion of configuration
RO->OH->RCO2>ROH>H2O, roughly correlated to basicity; stronger base, more likely it is attracted to positivity charged proton
Best are those that are stable when they leave. generally, the weaker the base, the better the leaving group. electron withdrawing effects and polarizablity also make for a good leaving group. The leaving group will always be more stable than the nucleophile.
Sn2 requires a ________ nucleophile, while nucleophilic strength doesn't affect Sn1
Sn2 reactions don't occur with a sterically hindered ________. Sn2 requires a methyl, primary, or secondary substrate, while Sn1 requires a secondary or tertiary substrate.
A highly polar ________ increases the reaction rate of Sn1 by stabilizing the carbocation, but slows down Sn2 reactions by stabilizing the nucleophile.
The ________ of an Sn2 reaction depends upon the concentration the substrate and the nucleophile, while the speed of an Sn1 depends only on the substrate.
_____ inverts stereochemistry about the chiral center, while ______ creates a racemic mixture
Acidity of alcohols
Acidity trend: methyl>1º>2º>3º
Grignard synthesis of an alcohol
R-Metal. R takes on a partial negative charge and so can attack the positive carbon of a carbonyl to produce an alcohol.
Reduction of an alcohol
Both NaBH4 and LiAlH4 will reduce aldehydes and ketones, but only LiAlH4 is strong enough to reduce esters and acetates.
Oxidation of alcohols
Primary alcohols can be oxidized to aldehydes using PCC and further oxidized to carboxylic acids using KMnO₄, Na₂Cr₂O₇, or CrO₃. Secondary alcohols can be oxidized to ketones using any of these oxidants.
A dehydration of an alcohol that results in an unexpected product. When hot sulfuric acid is added to an alcohol, the expected product is an alkene. However, if the alcohol is a vicinal diol, the product will be a ketone or aldehyde.
3 membered cyclic ethers. More reactive than typical ethers due to ring strain. React with water in the presence of an acid to form diols. Anti-addition
Acidities of functional groups
alkane < alkene < H2 < NH3 < alkyne < aldehyde < alcohol < water < COOH