Orgo 6.21-6

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Orgo 6.21-6
2013-10-30 07:03:25
CHM 201

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  1. __ is the singly most imp. factor ind etermining E1 or E2. IWhy?
    • nature of base
    • strong base--> rate of bimolecular reaction will be greater than the rate of ionizatio= E2
    • no strong base= good solvent makes a unimoelcular ioniization likely; loss of proton of weak base--> E1

    • E1: base strength unimportant
    • E2: requires strong bases
  2. The slow step of the E1 reaction is __. Like SN1 E1 critically depends on __. 
    In the E2 reaction, the TS spreads out the __ of the base over the entire molecule. There is no more good for __ in the E2 TS than in the reactants. The E1 is less sensitive tot eh __; in fact, some reagents are stronger bases in __.
    • formation of two ions
    • polar ionizing solvents
    • - chanrge
    • slvation
    • solvent
    • less polar solvents
  3. Summarize solvent comparison and substraet.
    • E1: requries good ionizing solvent
    • E2: solvent polarity not as imp.

    E1 and E2: tertiary > secondary > primary (primary will not go E1)
  4. In the E1 reaction, the __ is formation of a carbocation, and the reactivity order reflects the stability of __. In the E2 reaction, the more __ generally form more substituted, more stable alkenes.
    • RLS
    • carbocations
    • highly subbed
  5. The rate of the E1 is proportional to the __, but not to the __. It is a __. 
    The rate of the E2 is proportional to __. It followsa __/
    • concentration of hte alkyl halide (RX)
    • concentration of the base
    • 1st order rate eq.
    • both the alkyl halide and base
    • second order rate eq.
  6. In most E1 and E2 elims with two or more possible products, the product with the most __ predominates, called __, adn the most highyl subbed product is __.
    • subbed double bond
    • Zaitsev's rule
    • Zaitsev product
  7. The E1 reaction begins with an __ to give a __. No particular geometry required. The E2 reaction takes place through a concerted mechanism that requires a __ arrangement of hte bonds to the atoms being eliminated. Th TS is usually __, but can be __ in rigid systems
    • ionization 
    • flat carbocation
    • coplanar
    • anticoplar
    • syncoplanar
  8. E1 reactions invove a __, which can __ usually by the shift of a __ or an __, to give a more stable carbocation.
    The E2 takes place in __ with __. __ is possible in E2.
    • carbocation intermediate
    • rearrange
    • aklyk gorup or a hydride
    • one step 
    • no intermediates
    • no rearrangement