Cl[CH2:2][C@H:3]1[O:8][C:7]([CH3:10])([CH3:9])[O:6][C@@H:5]([CH2:11][C:12]([OH:14])=[O:13])[CH2:4]1.CC(Cl)(C)C.[Cl-].CN1CCCC1=[O:27]>C([O-])(=O)C.C([N+](CCCC)(CCCC)CCCC)CCC>[OH:27][CH2:2][C@H:3]1[O:8][C:7]([CH3:10])([CH3:9])[O:6][C@@H:5]([CH2:11][C:12]([OH:14])=[O:13])[CH2:4]1Solid tetrabutylammonium acetate obtained as above (111 g, 0.368 mole) was added in one portion to a mechanically stirred solution of the chloride (4R-cis)-6-(chloromethyl)-2,2-dimethyl-1,3-dioxane-4-acetic acid, 1,1-dimethylethyl ester prepared in step (d) above (35 g, 0.125 mole) in HPLC grade 1-methyl-2-pyrrolidinone (504 ml) under argon. The resulting solution was stirred at 85° C. (internal temperature). After 30 to 60 minutes the reaction mixture became homogeneous and brown in color. The progress of the reaction was followed by TLC and GC analysis. (TLC: Rf=0.63 for the chloride starting material; Rf =0.54 for the title compound (silica gel, Ethyl acetate:Hexane, 1:1, visualization by Ce(SO4)2 spray). GC: Rt =7.20 minutes (starting material) and 8.66 minutes (title compound).) After 11 hours the reaction was completed.
Wird geladen…
