chloride (4R-cis)-6-(chloromethyl)-2,2-dimethyl-1,3-dioxane-4-acetic acid, 1,1-dimethylethyl ester → (4R-cis)-6-[(Acetyloxy)methyl]-2,2-dimethyl-1,3-dioxane-4-acetic acid, 1,1-dimethylethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Solid tetra-n-butylammonium acetate prepared in step (e)(i) of Example 1 above (106.2 g, 0.352 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) of Example 1 above (32.7 g, 0.117 mole) in HPLC grade 1-methyl-2-pyrrolidinone (471 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 =0.54 for the title compound; Rf =0.63 for the chloride starting material (silica gel, Ethyl acetate:Hexane, 1:1, visualization by Ce(SO4)2 spray).) After 9 hours the reaction was completed.

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