Cesium carbonate → (2S,3R,6S)-4-[4-(4-hydroxy-4-methyl-pent-2-ynyloxy)-benzenesulfonyl]-2,6-dimethyl-morpholine-3-carboxylic acid methyl ester

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Reaction Steps

(2S,3R,6S)-4-(4-Hydroxy-benzenesulfonyl)-2,6-dimethyl-morpholine-3-carboxylic acid methyl ester, (200 mg, 0.607 mmol) (prepared according to the methods described in U.S. patent application Ser. No. 60/096256, filed Aug. 12, 1998) was dissolved in dimethyl formamide (6 mL). 5-Iodo-2-methyl-pent-3-yn-2-ol (272 mg, 1.214 mmol) and cesium carbonate (593 mg, 1.821 mmol) were added and the reaction stirred at room temperature for 4 hours. The reaction was diluted with diethyl ether (100 mL) and washed with water (5 times 10 mL) and brine (30 mL), dried over anhydrous magnesium sulfate and concentrated in vacuo to yield the title compound. The crude material was used directly in the preparation of Example 1 without further purification. 1HNMR (400 MHz, CDCl3): δ=7.70 (d, J=8.9 Hz, 2H), 7.0 (d, J=8.9 Hz, 2H), 4.74 (bs, 2H), 4.50 (q, J=6.6 Hz, 1H), 4.26 (s, 1H), 3.92 (m, 1H), 3.54 (s, 3H), 3.50 (m, 1H), 2.93 (dd, J=12.3 and 11.0 Hz, 1H), 1.48(s, 6H), 1.44 (d, J=5.4 Hz, 3H), 1.01(d, J=6.0, 3H). MS: Calculated for C20H27NO7S (M−OH): 408.15. Found: 408.1.

Provenance & Evidence