RT Book, Section
A1 Flygare, John
A1 Renslo, Adam
A2 Renslo, Adam
SR Print(0)
ID 1124842878
T1 Radical Chemistry
T2 The Organic Chemistry of Medicinal Agents
YR 2016
FD 2016
PB McGraw-Hill Education
PP New York, NY
SN 9780071794213
LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1124842878
RD 2024/04/19
AB In  this  chapter  we  will  examine  the  homolysis  (homolytic  cleavage)  of  σ  bonds  to  form  highly  reactive  radical  species.  When  a  bond  breaks  homolytically,  the  two  electrons  of  the  breaking  bond  end  up  on  different  atoms.  The  resulting  radical  species  possess  a  single  unpaired  electron  on  an  atom  lacking  a  full  octet  of  electrons.  This  makes  radicals  very  electron  deficient  and  unstable.  They  are  often  formed  in  low  concentrations  and  are  rarely  stable  enough  to  isolate,  though  they  can  serve  as  intermediates  in  chemical  processes,  as  we  will  see.  Biological  systems  take  advantage  of  the  high  reactivity  and  transient  nature  of  radicals  to  mediate  a  host  of  transformations  required  for  life.  Molecular  oxygen  exists  as  a  diradical  and  we  will  see  how  it  acts  as  a  powerful  oxidant,  attacking  organic  molecules  to  initiate  radical  reactions.  These  oxygen-mediated  radical  reactions  cause  cellular  damage  and  we  will  take  a  close  look  at  how  the  antioxidant  vitamins  E  and  C  (Figure  8.1)  prevent  this  damage  by  acting  as  radical  scavengers.