反应详情

A solution of 17-ethyl-1-hydroxy-12-[2'-(4"-triisopropylsilyloxy-3"-methoxycyclohexyl)-1'-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9 ]octacos-14,18-diene-2,3,10,16-tetraone in toluene containing a catalytic amount of acetic acid is treated with a catalytic amount of tetrakis(triphenylphosphine)palladium(0). After 5 minutes, 1.1 equivalents of tri-n-butyltin hydride is added and the reaction is stirred at RT until the proton NMR of an aliquot indicates that the reaction is complete. After quenching the reaction mixture with water and extraction with ether, the ether extracts are washed with brine and dried over magnesium sulfate. Chromatography of the residue over SiO2 yields 17-ethyl-1-hydroxy-12-[2'-(4"-triisopropylsilyloxy-3"-methoxycyclohexyl)-1'-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9 ]octacos-18-ene-2,3,10,16-tetraone. Alternatively, the enone can be reduced by dissolving this material (350 mg) and 15 mg of 5% Rh/C in 10 ml of ethanol or ethyl acetate and stirring under a hydrogen atmosphere. When the reaction is complete (tlc and/or 1H NMR), the mixture is filtered through diatomaceous earth, concentrated and the residue subjected to flash chromatography (75% CH2Cl2 : 5% MeOH: 20% n-hexane) to give 294 mg of the titled compound.

1. customAfter quenching the reaction mixture
2. extractionwith water and extraction with ether
3. washthe ether extracts are washed with brine
4. dry with materialdried over magnesium sulfate