Crystal structure analysis of synthetic cholestrol compounds-Vitamin D3-analogues

The title compound 1 (24-(S)-Hydroxycholesta-1,4-dien-3-one) crystallises in orthorhombic space group P2<SUB>1</SUB>2<SUB>1</SUB>2<SUB>1</SUB> with z=4.The unit cell dimensions are a=7.5882(9)Å, b=10.0745(14)Å, c=31.2553(23)Å, V=2389.4(5)Å<SUP>3</SUP>, D<SUB>cal</SUB>=1.108Mg/m<SUP>3</SUP>. The title compound 2 (24-(R)-Hydroxycholesta-1,4-dien-3-one) crystallises in monoclinic space group C2 with two molecules per assymetric unit and with Z=8. The Unit cell dimensions are a=16.752(4)Å, b=12.578(4)Å, c=23.160(5)Å, β=96.43(2)°, V=4849.0(2)Å<SUP>3</SUP>, D<SUB>cal</SUB>=1.092Mg/m<SUP>3</SUP> . In compound 1 and in both the molecules of compound 2 the ring A deviates from planarity,the rings B &amp; C are in chair conformation and the five membered ring D is in envelope conformation. The priority sequence attached to the chiral carbon C24 has 'S' designation in compound 1 and 'R' designation in compound 2. The structures are stabilized by O-H—O hydrogen bonds