11α,15α-Dihydroxyandrost-4-ene-3,17-dione

The title compound, C19H26O4, was biotransformed from androstenedione. In the crystal, intermolecular O—H⋯O hydrogen bonds link molecules into a corrugated sheet, which lies parallel to the ab plane. Ring A has a slightly distorted half-chair conformation, rings B and C adopt chair conformations, while the cyclopentane ring D adopts a 14α-envelope conformation.

The title compound, C 19 H 26 O 4 , was biotransformed from androstenedione. In the crystal, intermolecular O-HÁ Á ÁO hydrogen bonds link molecules into a corrugated sheet, which lies parallel to the ab plane. Ring A has a slightly distorted half-chair conformation, rings B and C adopt chair conformations, while the cyclopentane ring D adopts a 14-envelope conformation.  (2008); Perez et al. (2006). For conformational analysis, see Cremer & Pople (1975 Table 1 Hydrogen-bond geometry (Å , ).   (Perez et al., 2006;Kollerov et al. 2008). The production of several high value steroid drugs is mostly derived from key compounds such as AD by chemical synthesis (Ahmad et al., 1992;Malaviya & Gomes, 2008).
Two types of intermolecular hydrogen bonds contribute to the formation of a two-dimensional corrugated sheet lying parallel to the ab-plane, Figure 2. The O3 hydroxyl hydrogen forms a hydrogen bond to hydroxyl atom O2 at (1-x,y,z) by unit translation along the a-axis. Hydroxyl oxygen O2 forms a hydrogen bond to the screw-related carbonyl atom O1 at (1-x,-1/2+y,1/2-z), Table 1.

Experimental
Reagents: Colletotrichum lini AS3. 4486 was obtained from Institute of Microbiology, Chinese Academy of Sciences and maintained on Potato Dextrose Agar at 4°C. Androst-4-en-3,17-dione was obtained from Tianjin Pharmaceutical Company.
Biotransformation: 50 mg of the androst-4-en-3,17-dione dissolved in 1 ml of ethanol was added to the culture after 24 h for growth and the reaction was allowed to proceed for 72 h. The mycelium was then removed by filtration.
Separation and purification: The biomass and the broth were extracted separately with EtOAc. All extracts were combined and dried (anhydr. MgSO 4 ). The solvents after filtration were evaporated under reduced pressure. The crude extracts were purified by Si gel column using dichloromethane/ether/methanol (25:2:1, v/v/v). The white powder was diffused with n-hexane/acetone at room temperature. Colorless prismatic crystals suitable for X-ray analysis were obtained. -1.00Å and U iso (H) = 1.2U eq (C) or 1.5U eq (C methyl ). The absolute configuration was assumed since the structure of the commercially obtained androst-4-en-3,17-dione used in the preparation was known. Figures   Fig. 1. A view of (I) with our numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.