Organic Chemistry Exam 3

The flashcards below were created by user dyamonda on FreezingBlue Flashcards.

  1. SN2 reactions
    • Second-order rate reactions 
    • biomolecular
    • happens in concetrated step 
    • attacks come from the back side by Nu
    • Nu attack then loss of LG
    • methly and primary react quickly wiith Nu attack 
    • secondary react more slowly 
    • tertiary dont react
    • May require proton transfer to start reaction and at end
  2. SN1 reactions
    • Step wise process
    • Loss of LG, forms carbocation, and then Nu attack
    • Unimolecular 
    • based on first order reaction
    • tertiary reactions quickly
    • primary and methyl barely react
    • Some require proton transfer whenever Nu is not neutral 
    • may require proton transfer to start reaction
    • OH is bad LG
    • Rearrangement may occur
  3. How to Determine if Reaction will occur Via SN1 or SN2?
    • the substrate-methyl ,primary favor Sn2 tertiary favor SN1
    • the LG -must have good leaving good
    • the Nu   -SN2( strong Nu) SN1(weak Nu)
    • The solvent -polar protic(SN1) or polar aprotic(SN2)
  4. polar protic solvents
    • solvents that contain at least one hydrogen atoms connected directly to an electronegative atom.
    • Used for SN1 reactions
  5. polar aprotic solvent
    • contains no hydrogen atoms that are connected directlyto an electronegative atom. 
    • used for SN2 reactions
  6. Solvolysis
    when the solvent functions as a Nu
  7. alkenes
    are compounds with double bond carbons
  8. E2 reactions
    • tertiary halides react better 
    • One concerted step
    • regiochemistry is important 
    • the more substituted alkene is the Zaitsev product/ major product
    • when both the substrate abd vase are sterically hindered the less substituted the Hoffan product is the major product
    • trans disubstitued
  9. Anti-coplanar
    • staggered
    • on the sameplane
  10. syn-coplanar
    • elclipsed 
    • on the same plane
  11. E1 reactions
    • first order rate reactions
    • tertiary halides react most readily while primary halides are nonreactive
    • a carboncation rearrangement occurs if it will produce a more stable carboncation intermediate 
    • occurs same as SN1 stepwise
  12. E&Z (sterodescriptors)
    • Used when alkenes possesses nonsimilar groups 
    • E describes priority groups on different sides
    • Z describes priority groups on the same side
  13. Predicting if and reaction will proceed vis E1 or E2?
    • E1-
    • base strenght not important 
    • needs ionizing solvent
    • first order rate
    • rearrangement are common
    • E2-
    • Strong base required
    • polarity of solvent not important 
    • second rate
    • rearrangement not possible
  14. Addition reactions
    • are characterized by the addition of two groups across a double bond
    • favorable at low temps
  15. hydrhalogenation
    • reactions are characterized by the addition of H and X across a pi bond 
    • X= Br, Cl
    • regioselective
  16. Markovnikov addition
    halogens are placed at the more substituted position
  17. anti-Markovnikov addition
    • less substituted area
    • Addidtion of HBr proceeds vis this process
  18. hydration
    addition of (H and OH) across a double bond
  19. Acid - Catalyzed hydration
    • addition of water in the presence of an acid 
    • which generally proceeds via a markovnikov 
    • carboncation intermediate which is attacked by water to produce an oxonium ion followed by deprotonation
  20. Oxymercuration-demercuration
    • achieves hydration of an alkene without carbocation. 
    • The reaction proceeds via a bridged intermiate called mercurinium ion (AcOHg)
    • when the mercury is removed it use demercuration
  21. catalyic hydrogenation
    • involves the addition of molecular hydrogen (H2) across a double bond in the presence of a metal catalyst. 
    • reduces  an alkene to a alkane
  22. heterogeneous catalyst
    • do not dissolve in the reaction medium 
    • ex. Pt,pd,Ni
  23. homogeneous catalysts
    • are soluble in the reaction medium 
    • most common are called Wilkinson' catalyst
  24. Halogenation
    involves the addition of Br2 or Cl2 across an alkene
  25. anti addition
    Places two halogens atoms on opposite sides of the pi bond
  26. Halohydrion Formation
    • when bromaination occurs in a non- nucleophilic solvent
    •  the product of Br and Oh across an alkene is called bromohydrin 
    • Oh is placed in the more substituted position
  27. dihydroxylation
    the addition of OH and OH across an alkene
  28. Poisoned catalyst
    • will catalyze the conversion of an alkyne into a cis alkene.
    • P-2
    • Lindlar catalyst
  29. geminal dihalide
    both halogens are connected to the same carbon atom
  30. vicinal
    two halogens are connected to the adjacent carbon atom
  31. tautomers
    constututional isomer that rapidly interconvert via the migration of a proton
  32. keto-enol tautomerization
    the interconversion between an enol and a ketones
Card Set
Organic Chemistry Exam 3
chapt 7,8,9,10
Show Answers