ppt 4 Flashcards
aryl group – symbolized by
Ar
used to describe fragrant substances
aromatic compounds/arenes
from coal distillate
benzene
from cherries, peaches, and almonds
benzaldehyde
from tolu balsam
toluene
- now used to describe cyclic organic compounds with:
- high degree of unsaturation
- remarkably stable and unreactive compared to alkenes
aromatic compunds/arenes
incorrectly believed that the double bonds of benzene rapidly shift back and forth
kekule
HUCKEL’S CRITERIA FOR AROMATICITY
- Have one _p orbital on each of its atoms.
- Be ___ or nearly ___, so that there is continuous overlap or nearly continuous
overlap of all 2p orbitals of the ring. - Have 2, 6, 10, 14, 18, or so forth pi electrons in the cyclic arrangement of 2 p
orbitals (4n+2 rule)
2p
planar
has a hydroxyl (-OH) group bonded to an sp3 hybridized C in aliphatic group
alcohols
ROH
has a hydroxyl (-OH) group bonded to an sp2 hybridized C in aromatic group
phenols
ArOH
a fuel additive, an industrial solvent, and a beverage
ethanol
a general disinfectant, commonly called carbolic acid
phenol
- can be thought of as organic derivatives of water in which one hydrogen is replaced by organic components
- have nearly the same geometry as water(approximately tetrahedral)
- have higher boiling points than alkanes (form H-bonds)
- both weakly basic and weakly acidic
alcohols and phenols
reversibly protonated by strong acids to yield oxonium ions, ROH2+
as weak lewis bases
protonate water in dilute aqueous solutions to yield H3O+ and alkoxide ion (RO-) or a phenoxide ion (ArO-)
as weak acids
compounds containing an oxygen atom bonded to two carbon atoms
- can be thought of as organic derivatives of water in which both hydrogens are
replaced by organic components - have nearly the same geometry as water(approximately tetrahedral)
- have lower boiling points than alcohols and phenols (no H bonds)
ether
the familiar “ether” of medical use; frequently used as a reaction solvent; was once popular as an inhaled anesthetic
diethyl ether
cyclic ethers with a 3-membered ring
epoxides
- behave differently from open-chain ethers or other cyclic ethers
- more reactive than other ethers because of ring strain
- used in making “epoxy” adhesives, resins, and coatings
epoxide
- sulfur analog of alcohols
- has a sulfhydryl/mercapto/thiol (-SH) group bonded to a hydrocarbon chain
- characteristic stench
- widespread in living organisms
thiols
due 3-methylbutane-1-thiol and but-2-ene-1-thiol
skunk scent
- part of proteins and enzymes (e.g. cysteine residues)
UNDERGOES REDOX REACTION
* can be oxidized by mild reagents (e.g. bromine or iodine) to yield disulfides, R-S-S-R
* disulfides can be reduced back to thiols by treatment with Zn and acetic acid
* thiol–disulfide interconversion is a key part of numerous biological processes (cross
linking of peptide chains)
thiols
- sulfur analog of ethers
- widespread in living organisms
thioethers/sulfides
- derivatives of ammonia (NH3) in which one or more hydrogens are replaced by alkyl or aryl groups
- tetrahedral geometry
- have various applications in the chemical industry as starting materials for preparation
of insecticides and pharmaceuticals - majority of pharmaceutical agents contain
- many of the common coenzymes necessary for biological catalysis
CHARACTERISTIC ODOR
* _______ – fish-like aroma
* _______ – putrid
amines
trimethylamine
diamine (putrescine)
contribute to the flavors and aromas of many foods and assisting in the biological
functions of many enzymes
produced in large amounts for use as solvents and as starting materials to prepare a host of other compounds
aldehydes and ketones
a carbonyl group(C=O) bonded to a H atom(terminal carbonyl group)
aldehydes
a carbonyl group (C=O) bonded to 2 C atoms (nonterminal carbonyl group)
ketones
an aldehyde; is a coenzyme involved in a large number of metabolic reactions (e.g., transamination)
Pyridoxal Phosphate (PLP)
a steroid hormone w/ ketone group; secreted by the adrenal glands to regulate fat, protein, and carbohydrate metabolism
Cortisol (Hydrocortisone)
produced for use in building insulation materials and in the adhesive resins that bind particle board and plywood
Formaldehyde (H2C=O)
widely used as an industrial solvent
Acetone [(CH3)2C=O]
not electronegative enough to stabilize a negative charge (unlike carboxylic acids and derivatives)
can’t act as leaving groups in nucleophilic substitution reactions
polarized because of because of high electronegativity of oxygen relative to carbon
- C – ____ polarized and electrophilic (Lewis acidic)
- O – ____ polarized and nucleophilic (Lewis basic)
C=O group in aldehyde
- contain an acyl group (RCO-) bonded to an electronegative atom/substituent that can act as a leaving group in substitution reactions
- contains a carboxyl group (carbonyl group anda hydroxyl group)
- major products of biochemistry occurring under oxidizing conditions
carboxylic acid
- can stabilize a negative charge and therefore can act as leaving groups in
substitution reactions (unlike aldehydes and ketones)
C=O group in carboxylic acid
the principal organic component of vinegar
acetic acid (CH3CO2H)
responsible for the rancid odor of sour butter
Butanoic Acid (CH3CH2CH2CO2H)
responsible for the aroma of goats (Latin caper, meaning “goat”) and dirty socks
Hexanoic Acid/Caproic Acid (CH3(CH2)4CO2H)
destructive distillation of ants
formic acid
formica
vinegar
acetic acid
acetum
dairy products
propionic acid
pion, fat
butter (particularly if rancid)
butyric acid
butyrum
valerian root
valeric acid
odor of goats
caproic acid
caper
- has acyl group bonded to OR orOAr
- formed from a carboxylic acid and an alcohol
- pleasant-smelling liquids that are responsible for the fragrant odors of fruits and flowers
esters
- found in pineapple oil
methyl butanoate
- found in banana oil
isopentyl acetate
a commonly used solvent; plastic balloon odor
ethyl acetate
used as plasticizers to keep polymers from becoming brittle
dialkyl phthalates
- cyclic esters
- common names based on number of members in the ring
designated by Greek letters
lactone
- has an acyl group bonded to a trivalent nitrogen atom
- formed from a carboxylic acid and ammonia/amines
amides
- abundant in living organisms—proteins, nucleic acids, and many pharmaceuticals
have amidefunctional groups - the least reactive of the common acid derivatives
- stable to the temperatures andaqueousconditions foundin living organisms
amide
2nd degree amide
lactam
- has an acyl group (RCO-) bonded to a halogen atom
- formed from a carboxylic acid and a hydrogen halide
- only found in laboratories but not in nature because of high reactivity
ACID/ACYL HALIDES
- has two acyl groups bonded to an oxygen atom
- formed from 2 carboxylic acids with loss of water
ACID/ACYL HALIDES
- no carbonyl group but treated as carboxylic acid derivatives
- analogous to carboxylic acids
- have a carbon atom with three bonds to electronegative atoms
- contain a multiple bond
nitrile
different connectivities of atoms
constitutional isomer
same connectivities of atoms
stereoisomers
due to rotation about single bonds
conformational isomers
due to restricted rotation
geometric isomers
two types of isomers
geometric and conformational isomers