DAT Orgo

• Major resonance structures are the most stable, have all full octets, the least charges, and the negative charge on the most electronegative ion
• Pi bonds always form from 2p-2p
• Sigma bonds always form from sp2-sp2
• Acidity is increased with positively charged ions and decreased with negatively charged ions
• Acidity increases going left to right, and going down.
• Electron withdrawing groups increase acidity
• Fluorine is less acidic than NO2 (amino)
• If the pKa of the area is less than the pH, it will deprotonate. If the pKa is higher than the pH, it will protonate.
• The number of stereoisomers is given by 2^n
• If the fischer projection of a sugar has the bottommost OH on the right, it is a D sugar. If it is on the left, it is an L sugar. D sugars rotate light clockwise while L sugars rotate light counterclockwise
• UV-Vis analyzes compounds with conjugated double bonds
• IR Spectroscopy Values

  • 1650-1750: C=O
  • 3000: C-H
  • large broad peak at 3000: OH
  • sharp peak 3200-3500: NH (one peak) or NH2 (two peaks)
  • 2200: CN
  • 1550-1650: double bond
  • one at 1500-1600, another at 1300-1400: NO2
• Degree of Unsaturation: (2C + 2 + N - H - X)/2
• CNMR:

  • 100-180: C=O
  • >200: aldehyde or ketone
• HNMR

  • 0.5-5: alcohols or amine
  • C=C: 4-6
  • 6-8: aromatic ring
  • 10: aldehyde
  • 10: phenol
  • 12-14: carboxylic acids
  • 11-13: amide
• In an extraction, the organic layer is at the top and is nonpolar. The aqueous layer is at the bottom and it is polar. It takes into acount density and polarity
• In recrystallization, dissolving an impure solvent with ahot solvent will purify nonvolatile solids
• Polarimetry separates compounds by chirality
• Distillation separates volatile liquids with a heat source and catching the liquid with the lower boiling point

  • Simple distillation: if the boiling point difference is greater than 25 degrees
  • Fractional distillation: if the boiling point difference is around 25 degrees
• Gas liquid chromatography determines the abundance of each compound in a liquid by separating them by boiling point
• Thin layer chromatography separates compounds by solubility and polarity. The most soluble and nonpolar travel the fastest and highest. The bottommost compounds are polar.
• Column chromatography uses silica gel to separate impure solvents by polarity
• Kinetic products form the fastest and are favored at low temperatures.

  Thermodynamic products form slowly and at high temperatures, and produce the more stable and substituted product.
• Protic solvents are prefered by SN1 and E1
• Aprotic solvents are prefered by SN2 and E2
• The most substituted alkene is the fastest forming elimination product
• For a compound to be aromatic, it cannot have any sp3 hybridization. Nonaromatic means that it does not meet the aromaticity rules, while antiaromatic means it only violates the Huckel rule
• When splitting a compound where one will receive a halide and the other will receive OH, the halide is on the more substituted one and the alcohol is on the less substituted one
• LDA attackes the less substituted side
• Unlike NaBH4, LiAlH4 can reduce esters and carboxylic acids
• Ortho/para activators include NH2, NHR, NHR2, OH, OR, CH3, and amide
• Ortho/para deactivators include F, Br, Cl, and I
• Meta deactivators include N(CH3)3, NO2, CHO, CO2H, CN, COCH3, and esters
• A strong base and a weak nucleophile causes an E2 reaction under all circumstances
• A strong base an a strong nucleophile causes SN2 when it is primary, E2 when it is secondary, and E2 when it is tertiary
• A weak base and a strong nucleophile will give SN2 when it is primary, SN2 when it is secondary, and SN1 when it is tertiary
• A weak base and weak nucleophile will give nothing when it is primary, and a mix of SN1 and E1 when it is secondary or tertiary
• Strong bases and weak nucleophiles include NaH, DBN, DBU, t-BuOK, LiN[CH(CH₃)₂] (bulky)
• Strong base and strong nucleophile includes OH, OEt, and OMe
• Weak base and strong nucleophile includes the halides, SH, RSH, SH2, and CN