Organic acid anhydride case, the name of the acyl group is enclosed in parentheses to avoid ambiguity in the name, e.g., (thioacetic) anhydride (CHC(S)OC(S)CH). When two acyl groups are attached to the same sulfur atom, the resulting compound is called a thioanhydride, e.g., acetic thioanhydride ((CHC(O))S). Organic acid anhydride An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride
Sulfonic acid Sulfonic acid A sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula R−S(=O)−OH, where R is an organic alkyl or aryl group and the S(=O)(OH) group a sulfonyl hydroxide. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, HS(=O)(OH), a tautomer of sulfurous acid, S(=O)(OH). Salts or esters of sulfonic acids are called sulfonates. A sulfonic acid is produced by the process of sulfonation. Usually