9/12/24 Flashcards
how to name ethers
when naming, the larger group is the parent alkane, the smaller group is the alkoxy substituent
what type of structure is tetrahydrofuran
it is a cyclic ether
why is cyclopropane high in energy
it has ring strain that deviates from 109.5 °
why are epoxides reactive? what are they
they are reactive intermediates that have high energy due to their angle strain, but they are made useful with their oxygen gorup
what type of boiling points do ethers have
since they cannot form hydrogen bonds they have similar boiling points to hydrocarbons with the molecular weights
how does the boiling point relate to the molecular weight of an ether
higher molecular weights correlate to higher boiling points due to more opportunities for London dispersion forces
how do alcohols and ethers of the same molecular weight compare in terms of boiling points
alcohols will have higher boiling points due to their ability to form hydrogen bonds
what are the strongest intermolecular forces
hydrogen bonding > Dipole dipole> london disperson forces
what are intermolecular forces? What do they help describe?
intermolecular forces describe the interactions between molecules and they explain melting and boiling points
what are the most important intermolecular forces and their relative strengths
hydrogen bonding> dipole dipole> dispersion forces
what atoms can exhibit hydrogen bonding
nitrogen, oxygen, fluorine
do ethers exhibit hydrogen bonding? what type of intermolecular forces do they exhibit
they do not exhibit hydrogen bonds, they only interact weakly through dipole dipole IMFs and disperson forces
what type of IMFs affect the boiling points of ethers?
they only experience dipole-dipole IMFs and dispersion forces so they interact weakly and. have lower boiling and melting points
what types of solvents are alcohols missable in?
They are missable in water due to their polarity
what does missable mean
it means that they can be mixed together
what does it mean for a solution to be immisable
it means the two compounds do not mix and form a layer, this is common with a polar and nonpolar substance
what is petroleum ether
it is a mix of hydrocarbons and it is not an ether, they are also nonpolar
what are the key features of an acid catalyzed hydration?
the mechanism proceeds with a strong acid (h30)
- has a carbocation intermediate (may rearrange with a 1,2 hydride or 1,2 methyl shift)
- there is no stereoselectivity
-it proceeds with markovnikov addition
the acid is regenerated as a catalyst
what is markovnikov addition
the hydrogen is added to the least substituted side (the side with more hydrogens) and this is driven by carbocation stability
what are the key features of oxymercuration demurcuration
The reagents are 1) Hg(OAC)2 and 2) NaBH4
It forms an alcohol through markovnikov addition of an alkene and proceeds through a anti addition so the hydrogen and alcohol are added to opposite sides
there are no rearrangements or carbocation intermediates
what are the features of a hydroboration oxidation
the reagents are 1) BH3 * THF 2) H2O2, OH
it proceeds via anti-Markovnikov addition
it is a concerted syn addition
what are the three primary drivers of reactions with alcohols
the oxygen in the OH group is nucleophilic and can react with electrophiles
the hydrogen in the OH group is weakly acidic and can react with strong bases
the OH can be converted into a good leaving group which allows for elimination or substitution reactions to occur
what are the conditions for a good leaving group, why is OH not a good LG
a good leaving group must be weakly basic and stable in solution, these are typically the conjugate bases to strong acids like (I, Br, Cl)
OH is not a good leaving group because it is not a weak base and is unstable in solution
when preforming a reaction with HCl what should we assume
we should assume that we are really reactimg H30 and that the chloride ion is in the solution
