ch 5 - Alcohols Flashcards
hydroxyl group
-OH (formula of ROH for alcohols)
alcohol as non-highest priority group
named as substituent, with prefix hydroxy-
phenols
hydroxy groups attached to aromatic rings
naming of substituents on phenols in relation to each other’s position
ortho (or o-): next to; meta- (or m-): separated by one carbon; para- (p-): on opposite sides of the phenol
causes of hydrogen bonding
increased melting points, boiling points and solubility in water
hydrogen bond
a hydrogen attached to highly electronegative atoms like nitrogen, oxygen or fluorine results in polarity; pulls electron density away from the less electronegative hydrogen atom (slightly positive H and slightly negative on other). Slightly positive H attracts partially neg of another molecule, generating this noncovalent force
primary alcohols to aldehydes
proceeds via pyridinium chlorochromate (PCC) - a mild anhydrous oxidant
geminal diols
1,1 - diols, produced from hydration of aldehydes
secondary alcohols oxidized to ketones
proceeds with PCC or any stronger oxidizing agent
primary alcohols to carboxylic acids
proceeds with strong oxidizing agent like chromium (VI), which is reduced to chromium (III) in the process (ex Na2Cr2O7 and K2Cr2O7); also CrO3
secondary alcohols to ketones
Na2Cr2O7 or K2Cr2O7, or CrO3
Jones oxidation
dissolving of a very strong oxidizing agent chromium trioxide (CrO3) with dilute sulfuric acid in acetone; oxidizes primary alcohols to carboxylic acids and secondary alcohols to ketones
mesylate
good leaving group formed by the protonation or reaction of hydroxyl groups of alcohols. compound containing functional group -SO3CH3, derived from methanesulfonic acid; prepared using methysulfonyl chloride and an alcohol in the presence of a base; anionic form is a S with two double bonds to O, a single bond to O-, and a methyl. can serve as a protecting group
tosylates
good leaving group formed by the protonation or reaction of hydroxyl groups of alcohols. contain the functional group -SO3C6H4CH3, derived from toluenesulfonic acid; produced by the reaction of alcohols with p-toluenesulfonyl chloride, forming esters of toluenesulfonic acid; form is a benzene with a methyl group para to a S double bonded on both sides to O, and bonded to O with an R group; can serve as a protecting group
how alcohols are used as protecting groups
aldehydes/ketones reacted with two equivalents of alcohol (diol or dialcohol) forming acetals (primary carbons with two -OR groups and a hydrogen atom) and ketals (secondary carbons with two -OR groups) which do not react with LiAlH4; after desired step is complete, can be reverted back via step called deprotection (H2O cat. H+)
are phenols acidic or basic
acidic because oxygen-containing anion is resonance-stabilizing by the ring
quinone
results from treating phenols with oxidizing agents; makeup is 2,5 cyclohexadiene-1,4-dione; to name a molecule, add quinone to name of parent phenol; resonance stabilized electrophiles; not necessarily aromatic; serve as electron acceptors in ETC in both photosynthesis and aerobic respiration
phylloquinone
vitamin K1
menaquinones
class of molecules of vitamin K2
hydroxyquinones
share same ring and carbonyl backbone as quinones but differ by the addition of one or more hydroxyl groups; have electron donating groups making them slightly less electrophilic than quinones (although still very reactive); naming: position of hydroxyl groups is indicated by a number, and total number of hydroxyl groups is indicated by a prefix with the substituent name hydroxy-
ubiquinone
biologically active quinone; also called coenzyme Q; vital electron carrier associated with complexes I, II, and II of the ETC. also can be reduced to ubiquinol - this capacity allows it to be an electron carrier within the phospholipid bilayer
