Otherwise amino acids are produced by enzymatic conversions of synthetic intermediates. Some amino acids are produced by enzymatic conversions of synthetic intermediates. Metabolites are the substrates, intermediates and products of metabolism. It is also a reagent in the synthesis of various pharmaceutical intermediates. However, they are of wide importance as chemical intermediates and precursors. Lactic acid and lactaldehyde are common intermediates. Glycerophospholipids are generally metabolized in several steps with different intermediates. A carbanion is one of several reactive intermediates in organic chemistry. These catalysts speed up the reduction of the hydroperoxide intermediates. Routes that involve fewer chlorinated intermediates have continued to attract interest. Such reactions are thought to proceed via sulfenic acid intermediates. There are numerous methods available to synthesize MDMA via different intermediates. The bacteria also evades macrophage-killing by neutralizing reactive nitrogen intermediates. Those with two heteroatoms are more likely to occur as reactive intermediates. Dow manufactures epoxy resin intermediates including bisphenol A and epichlorohydrin.