First Order Elimination generally follows the following form:
General Mechanism: The first step requires the loss of the leaving group, forming a carbocation intermediate. A base then attacks a neighboring hydrogen forming the double bond.
Rate Equation: Rate = kr[R-X]
Points to Watch:
| Solvent Effects: | Solvent polarity is unimportant. Works best in a good ionizing solvent |
| Substrate Effects: | Highly substituted substrates work best 3 deg > 2 deg. Primary and methyl halides don't react. |
| Stereochemistry: | No special stereochemistry required |
| Effect of Base: | Base strength is unimportant because the base is not involved in the rate-determining step |
| Rearangements: | Since E1 goes by carbocation intermediate, rearangements can occur. |
| Leaving Group | Good leaving group required (ie. halide, tosylate, etc) |
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