Organic Chemistry Flashcards
Elements of Unsaturation
(CnH2n+2) - X
1 db= 1 unsat 1 tb = 2 unsat 1 ring=1 unsat
Boilping point
BP increases with incrased carbons. polar groups (EN atoms) will incnrease BP the heavier the polar group the higher the BP hydrogen bonds increase BP the most
Nucleophile
Lewis base (electron donor with bond formation)
electrophile
lewis acid (electron acceptor)
Conjugate bases + Stability
Stronger an acid, the more stable it’s conjugate base. Stability due to: 1. HIgher EN of an atom in conjugate base (applies for atoms in same row) 2. larger size (size applies for atoms in same column) 3. resonance stabilization
Common naming method
1C: form- 2C: acet- 3C: propion- 4C: butyr-
What is dis
Glycine
Alanine
serine
aspartic acid
cysteine
Amine
imine
amide
thiol
homolytic bond cleavage
one electron of the bond being broken goes to each fragment of the molecule
heterolytic bond cleavage
both electrons of the bond end up on the same atom (forms anion and cation)
anti conformation
largest group is 180 degrees apart
gauche conformation
larger group is 60 degrees apart
chair conformation stability
substitued groups are more stable in equatorial position
number of possible isomers formula
2^n chiral centers
enantiomer
non superimposable mirror images
RR/SS + SS/RR
diasteriomers
superimposible
SS/RR + RS/SR
melting point and boiling point of hydrocarbons
branching decreases
increased weight increases
Free Radical Halogenation
Initiation: X-X >>hv>> X* + X*
Propagation R-H + X* >>> R* + HX
R* + X–X >>> R—X + X*
Termination: X* + X* = X–x
R* + R* >>>> R-R
R* + X* >> R–X
Peroxides inhibit this rxn
Racemized product
Nucleophilicity
Increases as - charge increases
increases going down periodic table in a group: F<cl></cl>
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going left in the periodic table</p>
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opposite of electronegativity trend</p>
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Sn2 Reaction
Reactivity of Substrate: CH3>> 1 >> 2 >> 3 (steric hindrance
stereochemistry: inversion
reaction rate= k [nuc][electro]
polar aprotic (no Hbonds)
strong non bulky nucs
Sn1 Reaction
Reactivity of substrate: 3>>2>>1
stereochem: racemization
reaction rate= k[electro]
protic Hbonding solvens
carbocation rearrangements take place
nonbasic weak nucs
E1 Reactions
3>> 2>> 1
stereochem: most substituted double bond trans over cis
reaction rate = k [haloalkene]
solvent: protic Hbonders
carbocation rearangement
weak bases high temp
E2 Reactions
3 >> 2 >> 1
stereochemistry: small bases yield most substituted; bulk yields least substituted
reaction rate= k[base][substrate]
polar aprotic non hbonder solvents
no rearrangements
strong bases;
Addition of Hydeogen halide to Alkene
marvoinokov addition of halide
alkene is nucleophile
Oxymercuration demercuration
markovinokov addition of OH
Hydrohalide addition to alkene in peroxides
anti markovinokov addition of BR
hydroboration oxidation
antimarkovinokov addition of OH
* 1.BH3 if this is the only step BH2 is added antimarkovinovoley
- h2o2, -oh
Hydration of alkenes
markovinokov addition of OH
Halogenation of Alkenes
chlorine or bromine
adds anti addition
racimization
epioxide formation from alkenes
alkene + peroxyacid = epoxide + carboxylic acid
MCBPA epoxidation with acidic/basic hydrolysis
If H20 is added after you get a transdiol
Potassium Permangate alekene reaction(s)
if basic solution added: cis-diol
if acidic solution added: cleavage into ketones/aldehydes
Hydrogenation (with Ni/Pd/ or Pt) of alkenes
syn- addition of H-H MUST USE CATALYST
hydrogenation of alkyne (H2 and catalyst)
complete halogenation
hydrogenation of alkyne with lindlar
syn addition
alkene + Na, NH3(l)
trans addition
Aromatic Substitution of benzene
halogenation: Ph-H + Cl2/ AlCl3 or Br2/FeBr3 >>>> Ph-Cl + HCl or Ph-Br + HBr
Nitration: Ph-H + HNO3 + H2SO4>>>> Ph-NO2 + H20
Alkylation: PhH + RCl/AlCl3 >>> Ph-R + HCl
Ring Activation groups
increase bonding to benzene;
lone pair of electrons on atom directly bonded to ring (electron donation group)
ortho para directors (halogens do this as well)
Ring deactivation groups
decrease bonding to benzene
+ charge or no electrons
electron withdrawing
meta directors
Reduction of aldehydes, carboxylic acids, ketones, and esters
carboxylic acids, esters, aldehyde: primary alcohol
ketone: secondar alcohol
Gringard reagents and carbonyl groups
reduces carbonyl to OH and adds the R group
Forming alkyle halides from Alcohols
ROH+ SOCl2 >> RCL
ROH+ PBR3 >> RBr
ROH+ HCl >> RCl + H2O
ROH + Cl2 >>> No reacion
hydroxide is a bad leaving group
PCC and primary alcohol
Changes OH to carbonyl; loses H+
secondary alcohol and pcc/kmno4
ketone
Wittig Reaction
changes ketone to Alekene bond
Imine Formation from ketone/aldehyde
Replaces O with N-R’
aldol condesation
basically doubles the molecule and one =O >> to -OH
iif and heat is added the OH (dehydration) is removed and forms a double bond
Carboxylic acid acidity
stability of the carboxylate ion makes carboxylic acids more acidic than alcohols
EWG increase acidity; EDG decrease acidity
Reduction of Carboxylic acids
yields primary alcohol
Carboxylic Acid to Acid chlorides
adding SOCL2, PCl3, PCl5
carboxylic acid to acid anhydride
R’COOH + RCOCL + Pyridine >>> RC=OOC=OR’ +PyridineCL
Carboxylic acid + alcohol
esterification; must be in acidic environment
Acid chloride + ammonia
forms amide basically replace Cl with NH2
Ester + amine
amide.
can be substituated
Reactivity of Carboxylic Acid derivatives
Saponification
Esters to Alcohols
RO=COR’ >>reducing agent>> RCOH + R’OH
