反应详情

The starting material for the process of this invention, compound 2, can be prepared as described in Nicolaou, K. C. et al., "A General and Stereocontrolled Total Synthesis of Leukotriene B4 and Analogues," J. Am. Chem. Soc., 106, 3548 (1984) or Hanson, R. M. and Sharpless, K. B., J. Org. Chem., 51 1922 (1986). Briefly, optically active (S)-glycidol THP ether is prepared from ascorbic acid as disclosed in Takano, S., Numata, H., Ogasawara, K., Heterocycles, 19, 237 (1982) and Baldwin, J. J., Raab, A. W., Mensler, K., Arison, B. H., McClure, D. E., J. Org. Chem., 43, 4876 (1978). The ether is reacted (-78°-25° C.) with two equivalents of the anion of 1-heptyne (1.0 equiv. of n-BuLi, 1.0 equiv. of TMEDA and THF, -78° C.) to afford a-[(tetrahydro-2H-pyran-2-yl)oxy]dec-4-yn-2(R)-ol which is then silylated (t-BuPh2SiCl, imidazole, DMF) to, compound 2.