Many compounds with desirable medicinal properties are isolated from natural sources and are thus referred to as natural products. However, a compound's medicinal properties are often known before the structure of the compound has been determined. Below are examples of compounds where the first proposed structure was incorrect (Angew. Chem. Int. Ed. 2005,44, 1012-1044). In each case, the corresponding correct structure is also shown. Incorrect. Identify the groups that possess a predictable chemical behavior Identify the functional groups present in the proposed structure of porritoxin. Select all that apply. NH OCH Proposed structure of portioxin Proposed structure of porritoxin alcohol ether aromatic ring amide alkene ketone