c11h18o2

from The Collaborative International Dictionary of English v.0.48
Undecolic \Un`de*col"ic\, a. [Undecylenic + propiolic.] (Chem.)
   Pertaining to, or designating, an acid, {C11H18O2}, of the
   propiolic acid series, obtained indirectly from undecylenic
   acid as a white crystalline substance.
   [1913 Webster]
    

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