Synthesis of (R)-[2- 2 H]Isopentenyl Diphosphate and Determination of Its Enantiopurity by 2 H NMR Spectroscopy in a Lyotropic Medium Aquiles E. Leyes and C. Dale Poulter* Department of Chemistry, 315 South 1400 East, RM Dock, Henry Eyring Building, UniVersity of Utah, Salt Lake City, Utah 84112 poulter@chemistry.utah.edu Received July 27, 1999 ABSTRACT The synthesis of (R)-[2- 2 H]isopentenyl diphosphate from D-mannitol 1,2:5,6-bis-acetonide in 10 steps is reported. Stereospecific incorporation of the label is achieved by a BF 3 -catalyzed NaCNBD 3 reduction of the enantiomerically pure (S)-isopropylidene oxirane intermediate. The enantiomeric excess of the penultimate precursor [2- 2 H]isopentenyl tosylate (>95% ee) was determined by 2 H NMR spectroscopy in a poly- γ-benzyl-L-glutamate/CH 2 Cl 2 liquid crystal at -50 °C. Isopentenyl diphosphate (IPP) 1 is the universal precursor of more than 23 000 isoprenoid metabolites identified to date. 2 Prominent members of this extensive family of compounds include cholesterol, 3 taxol, 4 steroid hormones, 5 and the cell membrane-stabilizing family of dolichols. 6 In eukaryotic organisms (animals, higher plants, yeast, etc.) IPP is bio- synthesized by the well-characterized mevalonate route, 7 whereas most bacteria and green algae synthesize IPP from 1-deoxy-D-xylulose. 8 The latter pathway was first reported by Rohmer and co-workers 8 in 1993 and is less well characterized. Interestingly, isoprenoids synthesized in plant plastids have been shown to originate from 1-deoxy-D- xylulose 9 while those synthesized in the cytosol are from mevalonate. The biogenesis of IPP as well as mechanistic details of the biosynthetic pathways have been elucidated primarily on the basis of in vivo and in vitro labeling experiments. 7-9 Such an approach requires precursor metabolites that are specif- ically labeled with either stable ( 2 H, 13 C) or radioactive ( 3 H, 14 C) isotopes. Our recent mechanistic studies of the reactions (1) Abbreviations used: IPP, isopentenyl diphosphate; PBLG, poly-γ- benzyl-L-glutamate;. (2) Poulter, C. D.; Rilling, H. C. Biosynthesis of Isoprenoid Compounds; Porter, J. W., Spurgeon, S. L., Eds.; Wiley: New York, 1981; Vol. 1, pp 162-209. (3) (a) Rothblat, G. H.; de la Llera-Mora, M.; Atger, V.; Kellner-Weibel, G.; Williams, D. L.; Phillips, M. C. J. Lipid Res. 1999, 40, 781. (b) Liscum, L.; Munn, N. J. Biochim. Biophys. Acta-Mol. Cell Biol. Lipids 1999, 1438, 19. (c) See also ref 2, Vol. 1, p 481. (4) (a) de Furia, M. D. Phytomedicine 1997, 4, 273. (b) Hajek, R.; Volicek, L.; Slavik, M. Neoplasma 1996, 43, 141. (c) Mukaiyama, T.; Shiina, I.; Iwadare, H.; Saitoh, M.; Nishimura, T.; Ohkawa, N.; Sakoh, H.; Nishimura, K.; Tani, Y.-i.; Hasegawa, M.; Yamada, K.; Saitoh, K. Chem.-A Eur. J. 1999, 5, 121. (5) White, R.; Parker, M. G. Endocr.-Relat. Cancer 1998, 5, 1. (b) Ecker, J. Cell 1997, 90, 825. (c) Beato, M.; Herrlich, P.; Schutz, G. Cell 1995, 83, 851. (d) See also ref 2, Vol 2, p 507. (6) a) Burda, P.; Aebi, M. Biochim. Biophys. Acta-General Subjects 1999, 1426, 239. (b) Grunler, J.; Ericsson, J.; Dallner, G. Biochim. Biophys. Acta- Lipids Lip. Metabol. 1994, 1212, 259. (c) See also ref 2, Vol. 2, p 305. (7) (a) Banthorpe, D. V.; Charlwood, B. V.; Francis. M. J. O. Chem. ReV. 1972, 72, 115. (b) Beyia, E. D.; Porter, J. W. Annu. ReV. Biochem. 1976, 45, 113. (8) (a) Rohmer, M.; Knani, M.; Simonin, P.; Sutter, B.; Sahm, H. Biochem. J. 1993, 295, 517. (b) Rohmer, M.; Seeman, M.; Horbach, S.; Bringer-Meyer, S.; Sahm, H. J. Am. Chem. Soc. 1996, 118, 2564. (9) Lichtenthaler, H. K.; Schwender, J.; Disch, A.; Rohmer, M. FEBS Lett. 1997, 400, 271. ORGANIC LETTERS 1999 Vol. 1, No. 7 1067-1070 10.1021/ol990875m CCC: $18.00 © 1999 American Chemical Society Published on Web 09/11/1999