Water → 2-[(Methylsulfonyl)oxy]acetic acid (3aS,4R,5S,6S,8R,9R,9aR,10R)-6-ethenyldecahydro-5-hydroxy-4,6,9,10-tetramethyl-1-oxo-3a,9-propano-3aH-cyclopentacycloocten-8-yl ester

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Reaction Conditions

Reaction Steps

Pleuromutilin (222.0 g, 0.59 mol) was dissolved in dichloromethane (2.25 L) under nitrogen and triethylamine (92 mL, 66.45 g, 0.66 mol) was added at ambient temperature over 15 min, during which time a slight exotherm (16.5 to 18.5° C.) was observed. After stirring for 30 min the solution was cooled to −15° C. over 20 min. A solution of methane sulphonyl chloride (52 mL, 77.5 g, 0.68 mol) in dichloromethane (430 mL) was added over 1.28 h at −9 to −15° C. The mixture was left to stir in the ice/salt bath at ˜−9° C. initially. The mixture was stirred for a total of 1.5 h during which time it warmed up to 1° C. Deionized water (1.15 L) was added slowly while maintaining the temperature below 12° C. The mixture was stirred for 20 min and the phases separated. The dichloromethane phase (wt=3.70 kg) containing the title compound (267.8 g at 100% yield) was used directly in Step 5a.

Provenance & Evidence