Imidazole → HCID 57253034, compound

Participants

Reaction Steps

A solution of 17-ethyl-1-hydroxy-14-triisopropylsilyloxy-12-[2'-(3",4"-di-hydroxycyclohexyl)-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 (80.9 gm, 8.65 mmol) in mixture of dimethylformamide (60 ml) and methylene chloride (30 ml) and imidazole (1.77 g) under N2 atmosphere was treated with t-butyldimethylsilyl chloride 1.74 g 11.55 mol). After stirring at RT for 16 hrs, the reaction mixture was poured into water (600 ml) and resultant suspension was extracted with ether. The combined extracts were washed with water (5 times), dried over magnesium sulfate and evaporated in vacuo. The residue was chromatographed over SiO2. Elution with methylene chloride-ethyl ether (100:10) yielded 17-Ethyl-1-hydroxy-14-triisopropylsilyloxy-12-[2'-(3"-t-butyldimethylsilyloxy-4"-hydroxycyclohexyl)-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 (1.71 g, 17%, rf=0.66), 17-ethyl-1-hydroxy-14-triisopropylsilyoxy-12-[2'-(3"-t-butyldimethylsilyl-4"-hydroxycyclohecyl)-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 (1.82 gm, rf=0.41) and 17-ethyl-1-hydroxy-14-triisopropylsilyloxy-12-[2'-(3"-hydroxy-4"-t-butyldimethylsilyloxycyclohexyl)-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 (1.67 gm, rf=0.31).

Provenance & Evidence