(RS)-3-[5-(tetrahydro-pyran-2-yloxymethyl)-isoxazol-3-yl]-benzoic acid methyl ester → (RS)-3-Oxo-3-{3-[5-(tetrahydro-pyran-2-yloxymethyl)-isoxazol-3-yl]-phenyl}-propionic acid tert.-butyl ester

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The title compound was prepared from (RS)-3-[5-(tetrahydro-pyran-2-yloxymethyl)-isoxazol-3-yl]-benzoic acid methyl ester [prepared from (Z)-3-(hydroxyimino-methyl)-benzoic acid methyl ester [CAS-No. 91186-80-0] by treatment with NCS, cat. amount pyridine in CHCl3 followed by addition of (RS)-tetrahydro-2-(2-propynyloxy)-2H-pyran and slow addition of Et3N in CHCl3 at 23° C.] by treatment with lithium tert.-butyl acetate according to general procedure K (method b). Obtained as a yellow oil (3.00 g).

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