Reaktion #335446

Reaktionsgleichung

17-ethyl-1,14-dihydroxy-12-[2'-(3",4"-dihydroxycyclohexyl)-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

sec-butenyl trichloroacetimidate

Trifluoromethanesulfonic acid

→

title compounds

17-Ethyl-1,14-dihydroxy-12-[2'-(3"-sec-butenyloxy-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

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONto mix for 5 minutes
2. 2
   SonstigeAfter 15 minutes the reaction was quenched by the addition of saturated sodium bicarbonate
3. 3
   Extraktionextracted with ethyl acetate (3×8 ml)
4. 4
   WaschenThe combined organics were washed with brine
5. 5
   Trocknendried over magnesium sulfate
6. 6
   SonstigePurification of the
7. 7
   Einengenconcentrate by preparative TLC on silica gel (ethyl acetate: hexane (1:1)+1% methanol)

Vorschrift

To a solution of 17-ethyl-1,14-dihydroxy-12-[2'-(3",4"-dihydroxycyclohexyl)-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 (150 mg in 3 ml 33% methylene chloride in cyclohexane) sec-butenyl trichloroacetimidate (62 μl neat) was added and the reagents allowed to mix for 5 minutes. Trifluoromethanesulfonic acid (2 μl neat) was added slowly via syringe and the mixture stirred at room temperature. After 15 minutes the reaction was quenched by the addition of saturated sodium bicarbonate and extracted with ethyl acetate (3×8 ml). The combined organics were washed with brine and dried over magnesium sulfate. Purification of the concentrate by preparative TLC on silica gel (ethyl acetate: hexane (1:1)+1% methanol) gave the title compounds (11 mg 4"-ether; 13 mg 3"-ether).

Quelle