Definition of Hemiacetal

A hemiacetal is a chemical compound that is organic and is formed when the chiral carbon is connected to two atoms of oxygen. One oxygen atom belongs to the alcohol (-OH) function group whereas the other oxygen is of ether (R-O-R). In simple words, the addition of alcohol to aldehyde results in a hemiacetal.


Hemiacetal Formation


Example of Hemiacetal:

An example of the hemiacetal is 1-methoxyethan-1-ol. In this case, every alkyl (R) group is methane, a CH3. This is known to be the simplest of all the hemiacetals.

1-methoxyethan-1-ol Structure


They can be synthesized in several ways which include partial hydrolyzing the acetals, adding the alcohol to the carbonyl carbon of aldehyde by nucleophilic addition, etc.

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