Calcium Carbonate → 4-Hydroxy-3-methyl-2-(prop-2-yn-1-yl)cyclopent-2-en-1-one

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Reaction Steps

A mixture of 1.95 g of crude (R)-3-methyl-4-nitroxy-2-(2-propynyl)-2-cyclopenten-1-one prepared in Example 1, 1.00 g of calcium carbonate and 30 ml of water was stirred at a temperature of 80°-85° C. for 5 hours. Then the reaction mixture was cooled and filtered through celite. Thereafter, the water layer was saturated with sodium chloride and extracted with methyl isobutyl ketone. The organic layer was separated, washed with an aqueous saturated sodium chloride solution dried over anhydrous magnesium sulfate and, then, concentrated. Thus, 1.28 g of (S)-4-hydroxy-3-methyl-2-(2-propynyl)-2-cyclopenten-1-one (chemical purity: 90.1%, [α]D23 : +15.0° (C=1.06, in chloroform), (R)-isomer/(S)-isomer=11.6/88.4) was obtained.

Provenance & Evidence