17-Ethyl-1-hydroxy-12-[2'-(4"-hydroxy-3"-methoxycyclohexyl)-1'-methylvinyl]-14-t-butyl-dimethylsilyloxy-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 → 17-Ethyl-1-hydroxy-12-[2'-(4"-oxo-3"-methoxycyclohexyl)-1'-methylvinyl]-14-t-butyldimethylsilyloxy-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

Participants

Reaction Steps

A solution of 17-Ethyl-1-hydroxy-12-[2'-(4"-hydroxy-3"methoxycyclohexyl)-1'-methylvinyl]-14-t-butyl-dimethylsilyloxy-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 (Example 4) (30 gm, 0.0331 mol) in acetone (200 ml) was cooled to 0° C. To the solution was added 16.5 mL of Jones reagent (prepared by dissolving 26.72 g CrO3 in 23 mL of concentrated H2SO4, then diluting the solution to 100 mL with H2O) (The reaction was monitored by TLC 20% acetone/hexanes). After 60 minutes, the reaction was complete and excess oxidant was destroyed by slow addition of 10 mL of 2-propanol. After 10 min., the mixture had become bright green, and the reaction mixture was diluted with 800 mL of water and 1 L of ether. The layers were separated and the aqueous layer was washed with four equal portions of ether. Each ether layer was sequentially washed with two equal portions of water, then twice with 1 M KHCO3 solution, then with brine (Virtually all of the green color was removed following the KHCO3 washes). MS: 796 (M+7). The ether layers were combined, dried over MgSO4, and concentrated to a pale yellow gum that was lyophilized from benzene to afford 26.8 g (89%) of the title compound as a white solid. MS 796 (M+7).

Provenance & Evidence