Descrição
In the title compounds, C22H29ClO3, (I), and C21H29ClO2, (II),
respectively, the B rings adopt a half-chair conformation and
the D rings adopt an envelope conformation. A twist of the
steroid skeleton of both compounds is observed. There is a
positional disorder of the acetoxy group of (II), with the
terminal atoms disordered over two positions with near equal
occupancy. Quantum-mechanical ab initio calculations using a
molecular orbital Hartree–Fock method were performed for
the isolated molecules, thus allowing the distinction within the
structural features of these two androstane derivatives of
which characteristics are intrinsic to the molecules and which
are due to packing effects. The skeletal twisting was found to
be innate to the molecules, while the acetoxy disorder is due to
packing effects
; Moreira, Vânia M. 
