Photoresist Chemicals Pregn-4-ene-3,20-dione,21-[[(2,5-dihydro-2,2,5,5-tetramethyl-1-oxy-1H-pyrrol-3-yl)carbonyl]oxy]-11-hydroxy-,(11b)- (9CI) Cas：65402-12-2 Molecular Formula：C30H42 N O6