Synthesis of isoflavonoid deuterium labeled polyphenolic phytoestrogens

Deuteration methods are described for the synthesis of new stable deuterium labeled isoflavonoids, [8,3',5'-D-3]-daidzein 4a, [8,3',5'-D-3]-formononet in 4b, [2',3',5',6'-D-4]biochanin A 4c, [6,8,3',5'-D-4]dihydrodaidzein 5a, [3,6,8,3',5'-D-5]-dihydrodaidzein 5b, [3,2',3',5',6'-D-5]-dihydrogenistein 5c and [2,4,8,10-D-4]-coumestrol 6, using D3PO4. BF3/D2O as a deuteration r eagent. Positions of deuterium labels and isotopic purities were determined by NMR and mass spectrometry. The relative ease of H/D exchange at the var ious aromatic sites is discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.