The crystal and molecular structure of 9α-fluoro-16α-methyl-11β,17,21-trihydroxy-1,4-pregnadiene-3,20-dione 21-acetate monohydrate

The synthetic steroid 9~-fluorol 6~-methyl1 lfl, 17,21-trihydroxy-l,4-pregnadiene-3,20-dione 21-acetate, Cz4HaIO6F, is a potent inducer of liver microsomal enzymes as well as a powerful glucocorticoid. The structure was determined from room-temperature counter-collected data by direct methods. The space ~oup is P2~2~2~ with cell dimensions a= 15.292 (3), b= 19.143 (3), c=7-808 (2) .~,. Din= 127, Dx= 1308 gcm -a and Z= 4 for the formula C24H3106F. H20. 2141 reflexions were collected and the structure was refined to an R index of 2.8 %. The molecules are hydrogen bonded to each other in such a way as to form long helices, with their axes along c, which in turn are hydrogen bonded to each other through the water of crystallization.