N
N
O
N
O
N
OH
O
NH 2
O
NHC(CH 3 ) 3
H
H
H
H
.CH 3 SO 3 H
Saquinavir
N
N
N
O
N
NHC(CH 3 ) 3
O
OH
OH
H
.H 2 SO 4
Crixivan
4.6.6 Structure of benzene
Kekule´ structure of benzene
In 1865, August Kekule ´ proposed the structure of benzene (C 6 H 6 ). According to his proposals, in benzene
(a) all six carbon atoms are in a ring;
(b) all carbon atoms are bonded to each other by alternating single and
double bonds;
(c) one hydrogen atom is attached to each carbon atom;
(d) all hydrogen atoms are equivalent.
H
H
H
H
H
H
Kekulé structure of benzene
Limitations of Kekule ´ structure The Kekule ´ structure predicts that there
should be two different 1,2-dibromobenzenes. In practice, only one 1,2dibromobenzene has ever been found. Kekule ´ proposed that these two forms
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CH4 ORGANIC FUNCTIONAL GROUPS