Cleavage of Alkynes and Alkenes Alkenes react with concentrated KmnO4 to produce intermediate glycols which react further to produce either carboxylic acids or ketones (depending on the original alkene substituents). E.g. R R conc.KMnO4 R-CO,H H -R" H "R" HO OH R 0( not isolated R" Ph、H conc.KMnO4 Ph-CO2H CH3CH2-CO2H H CH2CH3 Alkynes also react with conc.KMnO to give carboxylic acids,and the same transformation can be achieved by the use of ozonolysis. E.g R-C=C-R'conc.KMnOa 001 R-C-C-R R-CO2H R'-CO2H 0r1)03 2)H20 not isolated Ch20 Carboxylic Acids (landscape) Page 13Ch20 Carboxylic Acids (landscape) Page 13 Cleavage of Alkynes and Alkenes Alkenes react with concentrated KmnO4 to produce intermediate glycols which react further to produce either carboxylic acids or ketones (depending on the original alkene substituents). E.g. Alkynes also react with conc.KMnO4 to give carboxylic acids, and the same transformation can be achieved by the use of ozonolysis. E.g. R' R'' R H H R HO R' OH R'' R CO2H O R' R'' not isolated H CH2CH3 Ph H conc.KMnO4 conc.KMnO4 Ph CO2H CH3CH2 CO2H