Octet / Collection
Study
Mnemonics and study methods for reactions, mechanisms and exams.
1-25 of 25 records
All Study
Mnemonics and study methods for reactions, mechanisms and exams.
SN1 vs SN2
SN1 vs SN2 - organic chemistry study tip. Mnemonic: SN2: Strong Nucleophile, Secondary or primary. SN2 works best with methyl and 1° substrates (steric hindrance matters). SN1 works best with 3° (carbocation stability matters). 2° can go either way - look at...
E1 vs E2
E1 vs E2 - organic chemistry study tip. Mnemonic: E2: Everything (H and LG) leaves at the same time. E2 requires anti-periplanar geometry (H and leaving group 180° apart). E1 makes the more stable carbocation first. Bulky bases favor elimination over substitu...
Zaitsev vs Hofmann Products
Zaitsev vs Hofmann Products - organic chemistry study tip. Mnemonic: Zaitsev = "Z" for "Ze more substituted" alkene. Zaitsev (most substituted alkene) is favored with small bases. Hofmann (less substituted) is favored with bulky bases like KOtBu or with poor...
Markovnikov's Rule
Markovnikov's Rule - organic chemistry study tip. Mnemonic: Rich get richer: H goes to C with more H's. In electrophilic addition, the electrophile (usually H⁺) adds to the carbon with MORE hydrogens, forming the more stable carbocation on the more substitute...
Anti-Markovnikov Addition
Anti-Markovnikov Addition - organic chemistry study tip. Mnemonic: Peroxides promote anti pattern. HBr + peroxides (ROOR) = anti-Markovnikov via radical mechanism. Only works with HBr (not HCl or HI). Hydroboration-oxidation also gives anti-Markovnikov alcoho...
Carbocation Stability
Carbocation Stability - organic chemistry study tip. Mnemonic: 3° > 2° > 1° > methyl (like a countdown). More substituted carbocations are more stable due to hyperconjugation and inductive effects. Watch for rearrangements (hydride and methyl shifts) to form...
Nucleophilicity vs Basicity
Nucleophilicity vs Basicity - organic chemistry study tip. Nucleophilicity = how fast it attacks carbon (kinetic, steric matters). Basicity = equilibrium with proton (thermodynamic, pKa matters). Good nucleophiles aren't always strong bases (e.g., I⁻, RS⁻).
R/S Configuration
R/S Configuration - organic chemistry study tip. Mnemonic: CORN rule or Steering wheel method. With lowest priority (#4) pointing away: clockwise = R (rectus = right), counterclockwise = S (sinister = left). Priority: higher atomic number > lower.
E/Z Configuration
E/Z Configuration - organic chemistry study tip. Mnemonic: Z = "Zame Zide" (same side), E = "Entgegen" (opposite). Use CIP priorities on each alkene carbon. If higher priority groups are on same side = Z. Opposite sides = E. Not the same as cis/trans!
Syn vs Anti Addition
Syn vs Anti Addition - organic chemistry study tip. Mnemonic: Syn = Same side, Anti = Across. Syn addition: both groups add to same face (hydroboration, epoxidation, OsO₄). Anti addition: groups add to opposite faces (Br₂, epoxide opening).
Inversion vs Retention
Inversion vs Retention - organic chemistry study tip. SN2 = inversion (Walden inversion). SN1 = racemization (both faces attacked). Mitsunobu = inversion. Curtius/Hofmann rearrangements = retention.
Axial vs Equatorial
Axial vs Equatorial - organic chemistry study tip. Mnemonic: Equatorial is more comfortable (less strain). Bulky groups prefer equatorial position to avoid 1,3-diaxial interactions. A-value = energy difference between axial and equatorial conformations.
Oxidation Reagent Selection
Oxidation Reagent Selection - organic chemistry study tip. Need aldehyde? Use PCC, Swern, or DMP (mild, stops at aldehyde). Need carboxylic acid? Use Jones, KMnO₄, or CrO₃ (harsh, goes all the way).
Reduction Reagent Selection
Reduction Reagent Selection - organic chemistry study tip. NaBH₄: aldehydes & ketones only. LiAlH₄: everything (aldehydes, ketones, esters, acids, amides). DIBAL at -78°C: ester → aldehyde.
Grignard Reaction Setup
Grignard Reaction Setup - organic chemistry study tip. Mnemonic: Grignard hates water - keep it DRY!. Grignard reagents react violently with any protic source (water, alcohols, amines). Use anhydrous ether or THF. Add acid workup AFTER the reaction.
Cross-Coupling Reagents
Cross-Coupling Reagents - organic chemistry study tip. Suzuki: boronic acid + Pd. Sonogashira: terminal alkyne + Pd/Cu. Heck: alkene + Pd. All require aryl/vinyl halide or triflate.
IR Key Peaks
IR Key Peaks - organic chemistry study tip. Mnemonic: Around 1700 = C=O, 2100-2300 = triple bonds, 3000-3500 = X-H. Broad peaks usually mean H-bonding (O-H, N-H). Sharp peaks are more characteristic. Carbonyl (1700 cm⁻¹) is the strongest, most diagnostic peak.
¹H NMR Integration
¹H NMR Integration - organic chemistry study tip. Integration tells you relative number of hydrogens. A 3:2:2 ratio with peaks at 1, 3.5, 4 ppm suggests CH₃-CH₂-O-CH₂ pattern.
NMR Splitting Patterns
NMR Splitting Patterns - organic chemistry study tip. Mnemonic: n+1 rule: n neighbors = n+1 peaks. A proton with 2 neighbors shows a triplet. A proton with 3 neighbors shows a quartet. Equivalent protons don't split each other.
Aldehyde NMR Signature
Aldehyde NMR Signature - organic chemistry study tip. Aldehyde proton appears 9.5-10 ppm (very deshielded). IR shows two peaks around 2700-2850 cm⁻¹ (Fermi doublet).
Predicting Products
Predicting Products - organic chemistry study tip. 1) Identify functional groups. 2) Recall reaction type (substitution, elimination, addition, etc.). 3) Consider regio- and stereochemistry. 4) Check for rearrangements.
Arrow Pushing
Arrow Pushing - organic chemistry study tip. Arrows flow from electron-rich (nucleophile) to electron-poor (electrophile). Show all electron pairs. Formal charges must balance across each step.
Retrosynthesis Strategy
Retrosynthesis Strategy - organic chemistry study tip. Work backwards from target. Identify disconnections (where to break bonds). Think about which carbon-carbon bond-forming reactions could make each bond.
Common Exam Traps
Common Exam Traps - organic chemistry study tip. Watch for: carbocation rearrangements, stereochemistry changes, protecting groups needed, acid/base incompatibility with other functional groups.
Functional Group Interconversions
Functional Group Interconversions - organic chemistry study tip. Master the "roadmap": Alkenes ↔ Alcohols ↔ Aldehydes/Ketones ↔ Carboxylic acids ↔ Esters/Amides. Know multiple routes to each functional group.
Study guides
Related study guides
Free, in-depth guides built around this material.