Hydrochloric Acid → (E)-6-[2-(2,4-Dichloro-6-(phenylmethoxy)phenyl)ethenyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-one

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Reaction Steps

Sodium tetrahydridoborate (1.55 g, 41.1 mmole) was added with stirring to a cooled solution (5° C.) of methyl (E)-7-(2,4-dichloro-6-phenylmethoxyphenyl)-5-hydroxy-3-oxo-6-heptenoate (34.8 g, 82.3 mmole) in ethanol (200 ml) at a rate sufficient to maintain the internal temperature at 15°-20° C. The resulting solution was stirred with ice-bath cooling for 15 min. and then acidified with 6N hydrochloric acid. The resulting mixture was diluted with water (500 ml) and extracted with ether (3×250 ml). The organic extracts were combined, washed with brine (4×100 ml), dried over magnesium sulfate and filtered. The filtrate was evaporated in vacuo, leaving the title compound as a yellow oil (34.8 g, 99.5%): pmr CDCl3) δ2.45 (2H, d), 3.65 (3H, s), 4.18 (H, m), 4.45 (H, m), 4.98 (2H, s), 7.28 (5H, s).

Provenance & Evidence