Difference Between Hemiacetal and Hemiketal

Key Difference – Hemiacetal vsHemiketal

Thekey differencebetween Hemiacetal and Hemiketal is that通过酒精和一种反应形成半斑醛而通过酒精和A之间的反应形成半蛋白酶酮。

半斑和半蛋白酶是有机化合物，可以观察到同一分子中包含两个官能基的杂化分子。羟小组和一个以太组。

内容

1.Overview and Key Difference
2.What is Hemiacetal
3.What is Hemiketal
4.Side by Side Comparison – Hemiacetal vs Hemiketal in Tabular Form
5.概括

What is Hemiacetal?

Hemiacetal是一种有机化合物，其中中央碳原子与四个不同的组键合。-OR组，-OH组，-r组和 - h组。A Hemiacetal is formed from an aldehyde. In contrast, if this compound is formed from a ketone, then it is called a Hemiketal. The chemical formula of Hemiacetal is RHC(OH)OR’. The “R” group is an alkyl group.

A Hemiacetal is formed when an alcohol is added to an aldehyde. In hemiacetal compounds, there are two types of bonds which represent the two starting molecules lead to the formation of the hemiacetal.

1. –C-O-H代表酒精。
2. –C-O-R键代表由醛的羰基形成的醚基。

A hemiacetal is formed when the –OR group of an alcohol attack the carbon atom of an aldehyde. (-OR group is formed when the hydrogen atom of ROH alcohol is released). The carbon atom of the aldehyde has a partial positive charge because of the difference betweenelectronegativityvalues of the carbon atom and the oxygen atom in the carbonyl group. The oxygen –OR group of alcohol can act as a nucleophile since it is rich with electrons. This nucleophile attacks the carbon atom of the carbonyl group of aldehyde, leading to a nucleophilic addition reaction. The result is hemiacetal. This reaction occurs in an acidic medium. Another way of formation of a hemiacetal is partial hydrolysis of an acetal.

What is Hemiketal?

半蛋白酶是一种有机化合物，其中中央碳原子与四个不同的组键合。-OR组，-OH组和两个-r组（彼此相同或不同）。从酒精和酮之间的反应形成半蛋白酶。The general chemical formula of a hemiketal is R₁R₂C(OH)OR’. Unlike in hemiacetal, there is no hydrogen atom directly bonded to the central carbon atom of the hemiketal.

The carbon atom of the carbonyl group of a ketone has a partial positive charge because of the difference between electronegative values of the carbon atom and the oxygen atom. Therefore, this carbon atom undergoes nucleophilic attack by the –OR group derived from an alcohol. The –OR group of the alcohol acts as a nucleophile since it is rich with electrons.

What is the Difference Between Hemiacetal and Hemiketal?

半斑vs Hemiketal
Hemiacetal是一种有机化合物，其中中央碳原子与四个不同的组键合。-OR组，-OH组，-r组和 - h组。	半蛋白酶是一种有机化合物，其中中央碳原子与四个不同的组键合。-OR组，-OH组和两个-r组（彼此相同或不同）。
形成
A hemiacetal is formed from the reaction between an alcohol and an aldehyde.	从酒精和酮之间的反应形成半蛋白酶。
存在氢原子
Hemiacetal的氢原子直接粘合到中央碳原子。	There is no hydrogen atom directly bonded to the central carbon atom of the hemiketal.
通式
The general chemical formula of Hemiacetal is RHC(OH)OR’.	The general chemical formula of a hemiketal is R1R2C(OH)OR’.

概括–半斑vsHemiketal

半斑and hemiketal are two forms of organic compounds containing two functional groups in the same molecule. The difference between Hemiacetal and Hemiketal is that hemiacetal is formed via the reaction between an alcohol and an aldehyde whereas a Hemiketal is formed via the reaction between an alcohol and a ketone.

Reference:

1. Libretexts. “Addition of Alcohols to Form Hemiacetals and Acetals.” Chemistry LibreTexts, Libretexts, 22 Aug. 2016.Available here
2. “Hemiacetal.” Wikipedia, Wikimedia Foundation, 23 Feb. 2018.Available here

Image Courtesy:

1.’Hemiacetal formation’By akane700 – Own work,(CC BY-SA 3.0)viaCommons Wikimedia
2.’Hemiketal formation’By akane700 – Own work,(CC BY-SA 3.0)viaCommons Wikimedia