≡ ≡
≡ ≡
Configuration: S Configuration: S Configuration: S
All Homomers (same compounds)
Configuration: 2R 3R Configuration: 2R 3R Configuration: 2R 3R
2R 3S
A B C
D E F
A, B & D : Same compound
B & C : Diastereomers
C & E : Enantiomers
[A/B/D] & F : Enantiomers
x & z : Same compound
[w or y] and [ x/z ] : Diastereomers
w & y : Enantiomers
x or z : Meso compound (inactive)
Even numbered rings with diagonally oppositely substituted do NOT show optical but DO SHOW geometrical isomerism
All other case MAY show optical isomerism and WILL Show geometical Isomerism
2 and 3 : both Cis and enantiomers of each other.
l and m : both cis and same compound (homomer) and MESO(inactive)
1 and 4 : both trans and enantiomers of each other.
k and n : both trans and enantiomers of each other.
1 vs [2 or 3] : diastreomers and cis trans of each other.
k vs [l or m] : diastreomers and cis trans of each other.
Both p and q are chiral and p_q is a site for geometrical isomerism (stereocentre)
Both p’ and q’ are chiral and p_q is a site for geometrical isomerism (stereocentre)
Both e and f are NOT chiral and p_q is a NOT a site for geometrical isomerism
Both e’ and f’ are NOT chiral and p’_q’ is a NOT a site for geometrical isomerism
p and q are 2 stereocenters (serving both optical and geometrical) HOWEVER for ONLY Geometrical Isomerism It will serves as single stereocenter.(Still 2 stereo centers for optical)
g is neither geometrical centre nor optical centre.
e, f, g and h all are stereo centre in total there are 4 stereo centre(optical + geo)
r, t and s are NOT chiral. Only one geometrical centre; only 2 geometrical
r, s and t are all stereo centres.
a & b are optical; a, b, c & d are geometrical; 4 total stereo centre
2 chiral with 1 pseudo chiral
Symmetrical groups (IMPORTANT)
Total 4 isomers with 2 chiral and 2 meso
3 chiral
UnSymmetrical groups (IMPORTANT)
23 = 8 isomers
4 chiral
Symmetrical groups (IMPORTANT)
Total 10 isomers with 8 chiral and 2 meso
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