16alpha,17alpha-Epoxy-20-oxopregn-5-en-3beta-yl acetate.
The title compound, C23H32O4, has a 3beta configuration, with the epoxy O atom at 16alpha,17alpha. Rings A and C have slightly distorted chair conformations. Because of the presence of the C5=C6 double bond, ring B assumes an 8beta,9alpha-half-chair conformation slightly distorted towards an 8beta-sofa. Ring D has a conformation close to a 14alpha-envelope. The acetoxy and acetyl substituents are twisted with respect to the average molecular plane of the steroid. The conformation of the molecule is compared with that given by a quantum chemistry calculation using the RHF-AM1 (RHF = Roothaan Hartree-Fock) Hamiltonian model. Cohesion of the crystal can be attributed to van der Waals interactions and weak intermolecular C-H.O interactions, which link the molecules head-to-tail along [101].
Andrade
L C
LC
Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, Portugal.
Paixão
J A
JA
de Almeida
M J
MJ
Martins
R M
RM
Soares
H I
HI
Morais
G J
GJ
Moreno
M J
MJ
Sá e Melo
M L
ML
Campos Neves
A S
AS
D018360:Crystallography, X-Ray; D015394:Molecular Structure; D011278:Pregnanes / Q000737:chemistry*; D011284:Pregnenolone / Q000031:analogs & derivatives / Q000737:chemistry*
C431292:16,17-epoxy-20-oxopregn-5-en-3-yl acetate; D011278:Pregnanes; D011284:Pregnenolone