(22S)-21-Acetoxy-11β-hydroxy-16α,17α-methylorthoacetoxypregna-1,4-diene-3,20-dione

In the title compound, methyl (22S)-11β-hydroxy-16α,17α-[(methoxy)(methyl)methylenedioxypregna-1,4-diene-3,20-dione-21-acetate, C₂₆H₃₄O₈, part of the orthoacetate group forms the dioxalane ring (E) fused with the steroid skeleton at the C16 and C17 atoms. Ring A is planar, rings B and C adopt chair conformations, while rings D and E have conformations midway between half-chair and envelope. Intermolecular O11—H...O3 hydrogen bonds are formed. The new chiral center at atom C22 of the dioxolane ring has an S configuration and the conformation of the ring, closed at C22, is comparable with the conformations found for the (22R) diastereoisomers of similar compounds.

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