How do you make pseudoephedrine?

Pseudoephedrine produced for commercial use is derived from yeast fermentation of dextrose in the presence of benzaldehyde. In this process, specialized strains of yeast (typically a variety of Candida Utilis or Saccharomyces Cerevisiae) are added to large vats containing water, dextrose and the enzyme pyruvate decarboxylase (such as found in beets and other plants). After the yeast has begun fermenting the dextrose, the benzaldehyde is added to the vats, and in this environment the yeast converts the ingredients to the precursor l-phenylacetylcarbinol (L-PAC). L-PAC is then chemically converted to pseudoephedrine via reductive amination.