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10 Cards in this Set
- Front
- Back
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Alcohol Nomenclature -ending if highest priority group - addition if not highest func. group - What is a phenol group position names if multiple groups on a benzene ring
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Formula : ROH functional group : -OH , Hydroxyl group replacing ending of name with -ol *if OH is highest priority group ex: Propanol -if not highest, hydroxy is in beginning with C#
Phenol: -OH group on aromatic ring - on benzene ring with multiple func. groups - positions named by Ortho, Meta, and Para -Ortho: func. groups on adjacent carbons -Meta: func group 2 carbons away - Para: func group is 3 carbons away |
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Physical Properties
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Intermolecular Hydrogen Bonding - signifigantly HIGHER melting & boiling points compared to hydrocarbons - more H bonding, higher BP and MP -H bonding: H atoms attached to high EN atoms ex: w/ Nitrogen, oxygen, Fluroine bc polarity - pull e- away from Hydrogen( becomes +) - allows for noncovaltn bond w/ (-) oxygen,etc. |
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Acidity of Alcohol - is alcohol a strong or weak acid? (remember it can donate a Hydrogen..) |
-OH is weakly acidic alcohols can dissociate into protons and alkoxide ions --similar to H2O --> H+ + -OH
pKA comparisons ( lower pKa= more acidic) pKa= -log(ka) *high Ka = lower pKa: strong acid (dissociates more) H2O OH- + H+ pKa 15.7 Methanol CH3O+ H+ 15.5 Propanol C2H5HO5 + H+ 15.9 PhOH -> PhO + H+ 10 |
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Phenols is phenol more/less acidic than most acids.. and why? Electron donating vs electron withdrawing groups on acidity |
lower pKa of 10 compared to other alcohols - aromatic ring allows more resonance stability - allows H-bonding--> high MP and BP -Slightly soluble in H2O (H bonding) - Can form salts with inorganic bases ex: NaOH - More electron donating groups: decrease in acidity or more basic -More electron withdrawing groups(high EN) increase in acitiy -More alkyl groups: decrease in acidity or more basic **Key point: acidity decreases (more basic) w/ more electron donating groups - donating groups destabilize the alkoxide anion - resonance withdrawing groups stabilize the alkoxide anion, which makes the alcohol more acidic |
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Alcohol Reactions |
Oxidation Reactions: - alcohols(1* and 2*) can be oxidized to several products * oxidation: more bonds to oxygen, less to H Pyridinium chlorochromate(PCC) - mild oxidizing agent, rxn stops at aldehyde/ketone ex: Primary alcohol --> Aldehyde Secondary Alcohol --> Ketone -anything stronger than PCC can also get ketone *PCC lacks the H2O to hydrate the easily hydrated aldehyde/ ketone..
-Aldehydes can easily react w/ oxidant to yield geminal diols (two -OH on end of chain) Strong oxidants: 1* OH w/ strong oxidant yield carboxylic acid ex: sodium Chromate (chromate alone does it) 2* OH w/ PCC or strong will yield Ketone - * |
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Jones Oxidation - Using CrO3: chromium trioxide |
*even stronger Chromium oxidizing agent w/ dilute H2SO4 in acetone.. Primary Alcohols ----> carboyxlic acids
Secondary alcohols----> ketones |
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Are -OH good leaving groups? -hint: they are nucleophiles many times.. Mesylates and Tosylates - are these good or bad leaving groups? -How good are they as protecting groups? |
Hydroxyl is poor leaving group for nucleophilic substitution rxns *can react to form Mesylates/Tosylates BETTER leaving groups mesylate: contains -SO3CH3 - methanesulfonic acid derivative in anionic form Tosylate: react an alcohol w/ toluenesulfonic acid -SO3C6H4CH3 - form esters of toluenesulfonic acid - looks like a benzene ring with a sulfur-ester-R if we do not want the alcohol to react in a rxn - mesylate and Tosylate are great protecting groups - wont react w/ reagents that would attack alcohols |
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Protecting Groups Acetals and Ketals What functional groups are prone to reducing agents? We can protect them by rxn w/ two equivalents of ______. |
alcohols can be used as protecting groups for other functional groups ex: aldehyde, ketone + 2 equivalents OH(diol) which will form acetals and ketals Acetals: 1* carbon with two -OR groups and a H Ketals: 2* carbons w/ two -OR groups b/c Carbonyls: very reactive w/ reducing agents ex: LiAlH4 will not react with acetal/ketal - can protect, then reduce other groups -deprotect: back to carbonyl, w/ aqueous acid |
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Phenol Reaction to Quinones |
*remember Hydrogen of -OH in Phenol very acidic. b/c stability of anion Oxidizing Phenols yield Quinones -remember oxidizing=more bonds to O -C-OH ------> C=O quinones can be nonaromatic - named by position carbonyl(s), add quinone to end b/c have carbonyls: electriphic C+ of C=O - serve as electon accepts biochemically ex: vitamin K1: a Phylloquinone - important w/ photosynthesis and carboxylation of some clotting factors in blood ex: vitamin K2: menaquinone class Hydroxyquinone vs hydroquinone -hydroxy, there is a higher functional group Hydro- only OH on the quinone
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Ubiquinone compare w/ ubiquinol Why is Coenzyme Q so important in ETC? |
Ubiquinone also called Coenzyme Q - vital electron carrier associated with * complexes I, II, and III of ETC -contributes to formation of proton motive firce across inner mito. membrane **most oxidized form Ubiquinone can be reduced(less bonds to O) to Ubiquinol upone accepting electrons (RIG) *redox capacity allows performed function |
