Orgo Not reaction things to memorize

Bromine Test

• Detects unsaturated compounds such as alkenes or alkynes

• Treat with bromine (Br2) in carbon tetrachloride (CCl4)

• Positive: Brown color disappears in alkenes and alkynes

• Negative: Brown color remains for alkanes

Baeyer Test

• Identifies unsaturated compounds such as alkenes or alkynes.

• Treat with dilute potassium permanganate (KMnO4)

• Positive: Purple color turns brown due to manganesse dioxide (MnO2) precipitate

• Negative: Remainds purple for alkanes

Silver Nitrate in Alcohol

• Detects alkyl halides.

• Treat with silver nitrate (AgNO3) in alcohol.

• Positive: Formation of a silver halide precipitate, indicating the presence of alkyl halides.

• Negative: No precipitate forms.

Iodoform Test

• Identifies methyl ketones or acetaldehydes

• Treat with iodine (I2) and sodium hydroxide (NaOH)

• Positive: Formation of yellow iodoform (CHI3) precipitate.

• Negative: No precipitate forms

Tollens’ Test

• Detects aldehydes

• Treat with Tollens’ reagent (Ag2O in NH3)

• Positive: Formation of a “silver mirror” confirms the presence of an aldehyde.

• Negative: No silver mirror forms

Lucas Test

• Identifies secondary. teritary, and benzylic alcohols

• Treat with alcohol mixed with zinc chloride (ZnCl2) and hydrochloric acid (HCl)

• Positive: Cloudiness indicates the presence of secondary or tertiary alcohols

• Negative: Primary alcohols remain clear.

Jones Test

• Identifies primary and secondary alcohols

• Treat with Jones Reagent (CrO3 in sulfuric acid)

IR, 3200-3500 cm peak

• Alcohol (-OH)

• Large, broad peak

IR, 3200-3500 cm

• Amine (N-H)

• Sharp peak

• Secondary amine (-NR2H): 1 peak

• Primary amine (-NRH2): 2 peaks

IR, 2500-3500

• Carboxylic acid (-COOH)

• Broad jagged peak

IR, 2200-2250

• Nitrile (C=-N)

• Medium peak

IR, 1700-1750

• Carbonyl , (C=O)

• Large, sharp peak

IR 1450-1600

• Aromatic (C=C)

• Medium peak

UV-Vis spectroscopy

• Used to analyze molecules with conjugated pi bonds

• A higher maximum absorption = more conjugated pi bonds

Ranking in order from downfiled to upfield for H NMR spectroscopy

Carboxylic Acid Derivatives > Aromatic > Ketone-adjacent protons

Signal Multiplicty

• Indicates the # of non-equivalent neighboring H+ and # of peaks/signal

• n + 1 rule, n = # neighboring H+ attached to adjacent carbonds

Carbon NMR Spectroscopy order from downfield to upfield

Ketone/aldehyde > Carboxylic Acid Derivatives > Aromatics

Degrees of Unsaturation

A pi bond or a ring each add one degree of unsaturation

Mass spectrometry

• Used to determine the mass of a compound

• Molecular Ion peak: the tallest peak in the rightmost section and represents the compound’s molecular mass

• Base peak: the tallest peak in the entire spectrum and the most stable molecular fragment

• m/z ration : mass of ion/charge of ion

Column chromatography

• Used to separate components in a mixture based on polarity, similar to TLC

• Non polar compounds travel faster and further down than polar compounds

Extraction

• Two immiscible liquids in a separatory funnel with a hydrophobic organic layer and a hydrophilic aqueous layer.

• Hydrophobic compound enters organic layer.

  • Typically top layer (less tense)

  • Except. if it has chlorine

• Hydrophillic compound enters aqueous layer

  • Typically the bottom layer.

• Like dissolves like, polar dissolves polar or non-polar dissolves non-polar

Distillation

• Separate a mixture of two miscible (able to mix) liquids with different boiling points.

• Simple distillation: boiling point of two liquids differ by at least 50 C. Liquid with lower boiling point is collected in flask because it boils out first.

• Fractional distillation: the boiling points differ by 25C or less. Liquid with lower boiling point comprises a larger portion of the vapor.

Thin Layer Chromatography

Separates compounds based on differing polarity/IMF strength.

• Mobile phase: Solvent (moves up TLC plate via capillary action)

• Stationary phase: solid absorbent

• Least polar compounds, travels further.

Recrystallization

• A method used to purify solids

• Heating the solids in a solvent and cooling the mixture.

• Solid being purified must have: high solubility at high temp, low solubility at low temp.

Liquid Gas Chromatography

• To determine relative abundance of compounds

• Components with higher boiling points travel slower and will have longer retention time.

  • Retention time similar to retention factor from TLC

Gauche/Staggered

• Bulky groups 50 apart, some steric strain

Eclipsed

• Least stable, high torisonal strain

• Fully eclipsed, highest energy

Anti

• Bulky groups 180 apart

• Most stable

Chiral center

• sp³ hybridized carbon with 3 unique substituents

Assigning R/S

1. Locate chiral center.

2. Assign priority, higher atomic # = higher priority.

3. If lowest priority on dash, assign R (clockwise) or S (counterclockwise). If on wedge, assign then reverse the designation.

Enantiomers

• Non-superimposable mirror images

• Opposite configuration at all chiral centers.

Diasteromers

• Non-superimposable, non-mirror

• Opposite configuration at some chiral centers

2^n rule

Max # of stereoisomers = 2 ^ # chiral centers

Optical activity

Chiral molecules rotate plane-polarized light

Enantiomers: rotate light equally but in opposite directions.

Will not rotate light if it has an internal plane of symmetry.

Racemic mixtures are optically inactive/

Acidity trend (CARDIO)

C- positive charge increase acidity

Atom: - increasing atomic radius increases acidity, and increasing EN

R- increases resonance = stronger acid

D - electronegative atoms increase acidity

O - orbital hybridization, more s character = stronger acid.

Meth-

1 carbon

Eth-

2 carbons

Prop-

3 carbons

But-

4 carbons

Pent-

5 carbons

Hex-

6 carbons

Hept-

7 carbons

Oct-

8 carbons

Non-

9 carbons

Dec-

10 carbons

Spiro compounds

1. count the number of carbons in each ring excluding the spiro center

2. List numbers lowest to highest inside the bracket

3. Write the alkane parent chain name after the bracket.

4. spiro[#.#]alkane

Bicylic Compounds

• Count the number of carbons in each ring excluding the bridgehead carbons.

• List numbers highest to lowest inside the bracket.

• Write the alkane parent chain name after the bracket.

• bicyclo[#.#.#]alkane

Priority ranking

Carboxylic acid (highest), acid anhydride, ester, acid halide, amide, nitrile, aldehyde, ketone, alcohol, thiol(SH), amine, alkene, alkyne, alkoxy, halogen, nitro, alkyl