Piperonal (heliotropine, protocatechuic aldehyde methylene ether) is an aromatic aldehyde that comes as transparent crystals, C₈H₆O₃, and has a floral odor. It is used as flavoring and in perfume. It can be obtained by oxidation of piperonyl alcohol or piperic acid. It is also a minor natural component of the extract of vanilla. It may be used in the synthesis of 3,4-methylenedioxyamphetamine (MDA). In one synthetic path, nitroethane in a glacial acetic acid solution with an ammonium acetate catalyst yields a substituted nitrostyrene via a condensation reaction. This intermediate can then be reduced in the presence of a strong reducing agent such as lithium aluminium hydride (LiAlH₄) to yield MDA. Read more... or Edit at Wikipedia...