| Abstrakt: |
The Pd(0) based synthesis of two disilyl synthons (Z-1-trimethylsilyl-6-tert-butyldiphenylsilylhex-3-ene-1,5-diyne (18) and Z-1-trimethylsilyl-6-triisopropylsilylhex-3-ene-1,5-diyne (19)) and the selective removal of the trimethylsilyl group (K2CO3, MeOH) to afford 24and 25is described. These building blocks are employed in the construction of the taxamycin-12 compound 38(16,17,18-trimethyl-2-methyloxymethoxy-9-hydroxybicyclo[9.3.1]pentadec-5-ene-3,7-diyne). The final ring closure to the 12-membered ring utilizes an intramolecular Cr–Ni mediated condensation of the iodoalkyne 37(1,3,3-trimethyl-2-(2-oxoethyl)-4-(Z-1-methyloxymethoxy-7-iodohept-4-ene-2,6-diynyl)cyclohexene). Keyword: cancer, enediynes, synthesis, Pd(0) coupling. |
