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

Participants

Reaction Conditions

Reaction Steps

Pleuromutilin (69.95 g at 90% purity) and triethylamine (26 mL, 18.33 g) in dichloromethane (0.55 L) were cooled to −10° C. Methane sulphonyl chloride (14.5 mL, 20.87 g) in dichloromethane (0.12 L) was added over 0.5 h at −5 to −10° C. After 0.5 h the mixture was warmed to 15-20° C. and water (0.25 L) added. The phases were separated and the aqueous phase was further extracted with dichloromethane (0.06 L). The combined dichloromethane solution was concentrated by distillation collecting 0.5 L. The distillation was continued by slowly adding propan-2-ol (0.3 L) and collecting a further 0.3 L to reach a solution temperature of 78° C. n-Heptane (0.29 L) was added slowly whilst maintaining the temperature between 75-80° C. The solution became turbid with the product crystallizing. The mixture was cooled to 0° C. and stirred for 1 h. The product was filtered off, washed with chilled 2:1 n-heptane/propan-2-ol (0.075 L) and dried under vacuum to give the title compound (75.33 g, 95.6%).

Provenance & Evidence