Orthoester

  In organic chemistry, an orthoester is a functional group containing three alkoxy groups attached to one carbon atom. The name can also refer to any organic compound that contains this functional group. An example of an orthoester is ethyl orthoacetate, CH₃C(OCH₂CH₃)₃. Orthoesters are used in organic synthesis as protecting groups for esters. Although orthoesters are not an ester themselves, they are called as such due to the ester function that appears when the orthoester is hydrolized. For example, trimethyl orthoformate ( CH(OCH₃)₃ )will be hydrolized (under acidic conditions) to methylmethanoate and methanol^[1].

Additional recommended knowledge

What is the Sensitivity of my Balance?

Daily Sensitivity Test

Daily Visual Balance Check

Reactions

Preparation

Orthoesters can be prepared by the reaction of nitriles with alcohols under acid catalysis:

RCN + 3 R’OH → RC(OR’)₃ + NH₃

Esterification

Orthoesters are readily hydrolyzed in mild aqueous acid to form esters:

RC(OR’) ₃ + H₂O → RCO₂R’ + 2 R’OH

References

1. ^ Clayden, Greeves, Warren and Wothers, Organic Chemistry (2001), p. 345