146 
Terpenes. 
( A.m.  Jour.  Pharm. 
1     March,  1886. 
The  author  confirms  Tilden's  statement  (Trans.,  1878,80  and  261), 
that  Russian  and  Swedish  oil  of  turpentine  contain  the  same  constit- 
uents, namely,  australene,  sylvestrene,  and  dipentene.  The  hydro- 
carbon obtained  by  decomposing  sylvestrene  chloride  with  aniline 
closely  resembles  sylvestrene,  but  the  identity  of  the  bodies  is  not 
proved.  The  hydrocarbons  yield  a  chloride  melting  at  72°,  and  a 
liquid  bromide. 
"  Terpinol"  described  by  Wiggers  (Annalen,  lvii,  252),  and  by 
List  (ibid.,  lxvii,  367),  does  not  exist. 
Terpin  hydrate,  C10H20Oo— H20,  melts  at  117°.  It  is  a  saturated 
compound,  and  is  decomposed  by  boiling  with  acids  or  dehydrating 
agents,  yielding  terpineol,  C10H18O,  and  other  products.  When  a 
mixture  of  1  part  of  sulphuric  acid  and  2  of  water  is  used,  terpineol, 
terpinene,  C10H16,  and  terpinolene  are  formed.  When  very  dilute 
sulphuric  acid  is  used,  the  chief  product  is  turpinene.  Dilute  phos- 
phoric acid  and  glacial  acetic  acid  on  the  other  hand  yield  terpineol 
as  the  principal  product.  Terpin  hydrate  is  almost  completely  con- 
verted into  dipentene  by  prolonged  treatment  with  potassium  py- 
rosulphate. 
Terpineol,  C10H17OH,  is  a  nonsaturated  monatomic  alcohol.  It  is  a 
thick  liquid,  boiling  at  215°,  and  is  sparingly  soluble  in  water.  It 
unites  with  bromine  to  form  an  unstable  bromide. 
Dipentene  tetrabromide,  melting  at  124°,  is  formed  by  the  action  of 
an  excess  of  bromine  on  terpineol.  The  hydroxy!  in  terpineol  is 
easily  replaced  by  chlorine  or  iodine,  yielding  for  example  the  chlo- 
ride, C10H18C12,  melting  at  50°,  and  the  iodide  melting  at  77°.  Ter- 
pineol unites  with  carbanil,  forming  phenylterpinylurethane,  which 
crystallizes  in  white  needles  melting  at  110°.  Boiling  with  dilute 
acids,  or  treatment  with  dehydrating  agents,  converts  terpineol  into 
terpene  or  dipentene,  but  if  terpineol  is  left  at  the  ordinary  tempera- 
ture in  contact  with  dilute  sulphuric  or  hydrochloric  acid,  it  unites 
with  water,  forming  terpin  hydrate,  C10H20O2+H2O. 
Terpin  has  the  same  boiling  point  as  dipentene,  but  the  two  com- 
pounds are  not  identical,  as  the  former  yields  a  liquid  bromine-deri- 
vative. Terpin  is  formed  by  the  inversion  of  pinene  with  alcoholic 
sulphuric  acid. 
Terpinolene  has  not  yet  been  obtained  in  a  pure  state.  It  boils  be- 
tween 185°  and  190°,  and  yields  an  unstable  tetrabromide  crystalliz- 
ing in  monoclinic  plates. 
