Octet

Octet / Reactions

E1 Elimination

E1 Elimination (E1 Elimination.) Converts CC(C)(C)Br to CC(C)=C using Weak base or heat. Conditions: Polar protic solvent, heat in Water or alcohol. Stereochemistry: No stereospecificity (unlike E2).

Elimination

Reaction details

Name

E1 Elimination

Type

Elimination

Subtype

E1

Starting Material

CC(C)(C)Br

Product

CC(C)=C

Reagents

  • Weak base or heat

Conditions

Polar protic solvent, heat

Solvent

Water or alcohol

Mechanism
  1. Smiles

    CC(C)(C)Br

    Description

    Tertiary bromide

  2. Smiles

    C[C+](C)C

    Description

    Step 1: Br⁻ leaves, carbocation forms (rate-determining)

  3. Smiles

    CC(C)=C

    Description

    Step 2: Base removes adjacent H, π bond forms

Stereochemistry

No stereospecificity (unlike E2)

Regiochemistry

Zaitsev: more substituted alkene favored

Tips

  1. Rate = k[substrate] - unimolecular

  2. Same conditions favor both E1 and SN1

  3. Carbocation intermediate can rearrange

  4. Competes with SN1

Related Reactions

  • e2-elimination

  • sn1-bromide

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Reactions

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Source collection

SN2 with Hydroxide

SN2 with Hydroxide (SN2 Substitution.) Converts CCBr to CCO using NaOH, KOH. Conditions: Polar aprotic solvent in DMSO, DMF, or acetone. Stereochemistry: Inversion of configuration (Walden inversion).

Substitution

SN2 with Cyanide

SN2 with Cyanide (SN2 Substitution.) Converts CCI to CC#N using NaCN, KCN. Conditions: Polar aprotic solvent in DMSO or DMF. Stereochemistry: Inversion of configuration.

Substitution

SN1 Solvolysis

SN1 Solvolysis (SN1 Substitution.) Converts CC(C)(C)Br to CC(C)(C)O using H₂O. Conditions: Polar protic solvent, heat in Water or aqueous ethanol. Stereochemistry: Loss of stereocontrol (planar carbocation attacked from either face → racemization if chiral ce...

Substitution

SN2 with Tosylate Leaving Group

SN2 with Tosylate Leaving Group (SN2 Substitution.) Converts CCOS(=O)(=O)c1ccc(C)cc1 to CCN=[N+]=[N-] using NaN₃. Conditions: Polar aprotic solvent.

Substitution

SN2 with Azide

SN2 with Azide (SN2 Substitution.) Converts CCBr to CCN=[N+]=[N-] using NaN₃. Conditions: Polar aprotic solvent.

Substitution

E2 Elimination

E2 Elimination (E2 Elimination.) Converts CC(Br)CC to CC=CC using KOtBu, NaOEt, NaOH (conc.). Conditions: Strong base, heat in t-BuOH or EtOH. Stereochemistry: Anti-periplanar geometry required. E/Z depends on which H is removed..

Elimination

Study guides

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