Abstract
A new total synthesis of the mycotoxin ochratoxin A (OTA) is presented, in which it is prepared in 9% overall yield from commercially available Substrates. The key step consists of the condensation reaction between protected L-phenylalanine and 5-chloro-8-hydroxy-3-methyl-1-oxoisochromane-7-carboxylic acid (ochratoxin alpha, OT alpha). The same strategy could be successfully applied to L-d(5)-phenylalanine, leading to the first total synthesis of d(5)-OTA a molecular tracer (or the detection and analytical quantification of the natural mycotoxin in food samples by means of stable isotope dilution assay (SIDA).