N-[(3β,4α,9β,16α,20S)-20-(dimethylamino)-16-hydroxy-4-(hydroxymethyl)-4,14-dimethyl-11-oxo-9,19-cyclopregnan-3-yl]-2-methylpropanamide 、
三甲基乙酰氯 在
吡啶 作用下,
反应 1.5h,
以45%的产率得到(20S)-16α-pivalyl-3-isobutyrylamino-9,19-cyclo-4α-pivalylmethyl-4,14α-dimethyl-20-dimethylamino-5α,9-pregnan-11-one