Question

How do I know which reaction to use for alcohols, ethers and epoxides? If somebody could please explain,, I would be SO appreciative. We just finished sn1, sn2, e1 and e2 reactions and I understand which reaction to use since we had a chart. No chart this time and I am lost. The reactions include, dehydration, Williamson ether, e1, e2, sn1, sn2 and please let me know if I'm missing anything else. Thank you!  

Answer 1

The reaction in Organic chemistry depends on the Functional group present in the compound, Reagent and conditions of the reaction.

Subsitution reaction are those in which a group/atom is replace by another group/atom. Their is no change in saturation level of product. Low temperature favours subsitution reaction. eg sn1 and sn2

In elimination reaction an atoms or group leave the compound ie it is eliminated. Their is change in saturation level of the product. High tempertaue favours elimination reaction.The product become unsaturated.eg e1 and e2.

In dehydration reaction water is lost in the reaction.

SN1: Substrate: Tertiary alkyl halide Reagent is dilute base Product is: Tertiary alcohol (Racemic mixture) .

SN2: Substrate: Primary alkyl halide Reagent is dilute base. Product is : Primary alcohol having inversion in configuration.

E1: Substrate: Tertiary alkyl halide Reagent is alcoholic base Product is: Alkene

E2: Substrate: Primary alkyl halide Reagent is alcoholic base. Product is : Alkene

In Dehydration reaction the reagent is Sulphuric acid, Alumina or Phosphorous pentaoxide.Product is unsaturated and loss of water occurs.

In williamsons ether synthesis, we use an alcohol and haloalkane in presence of strong base to give product ether.

SN1 and SN2 is used for the synthesis of alcohol.

Dehdration reaction alcohol can be dehydrated to alkene.

Williamson synthesis is used in synthesis of ether using alcohol as substrate.