7 Appendix
201
Table 22 (continued)
Groups protruding from the projection plane have their bonds in bold print and the
designator p; those receding behind this plane are shown with broken bonds and the
descriptor a.
H
Me
H
5a-Gonan
5 p-Estrane
Undulated bonds and the designator ~ are used when it is not intended or possible to
specify the actual steric orientation of a group.
R
Trivial name
H
5';-Androstane
2021
C2HS
5';-Pregnane
20
CH(CH3)CH2CH2CH3
S~-Cholanea
H
20
CH(CH3)CH2CH2CH2CH(CH3h
5~-Cholestanea
20
24
CH( CH3)CH2CH2CH (CH3)CH( CH3h
5~- Ergostane a, b
20
24
CH (CH3)CH2CH2CH( C2Hs)CH (CH3h
5~-Stigmastane a,c
a 20R, b 245, c 24R configuration.
H
H
Me
Me
Me
Me
5a-Lanostane
5a- Protostane