酯

Esters are chemical compounds derived formally from an oxoacid (one containing an oxo group, X=O), and a hydroxyl compound such as an alcohol or phenol.酯是形式上衍生自含氧酸（一種含氧代基團，X ＝ O）和羥基化合物如醇或苯酚的化合物。 Esters are usually derived from an inorganic acid or organic acid in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group.酯通常衍生自無機酸或有機酸，其中至少一個-OH（羥基）被-O-烷基（烷氧基）取代。
Esters are ubiquitous.酯無處不在。 Many naturally occurring fats and oils are the fatty acid esters of glycerol.許多天然存在的油脂是甘油的脂肪酸酯。 Esters with low molecular weight are commonly used as fragrances and found in essential oils and pheromones.低分子量的酯通常用作香精，並存在於香精油和信息素中。 Phosphoesters form the backbone of DNA molecules.磷酸酯形成DNA分子的骨架。 Nitrate esters, such as nitroglycerin, are known for their explosive properties, while polyesters are important plastics, with monomers linked by ester moieties.硝酸酯，例如硝酸甘油，以其爆炸性而著稱，而聚酯是重要的塑料，其單體通過酯部分連接。
本文將主要討論衍生自羧酸和醇類的酯，這是最常見的酯類。