One such conversion involves tosyl chloride,and the formation of a tosylate (These compounds undergo substitution and elimination very easily,often more reactive than alkyl halides). OH TsCl Nuc: ·-OTs pyridine (substitution) or elimination: B一H+OTs (elimination) B: Cyclohexanol will not reduce with LiAlH,but the corresponding tosylate reduces to cyclohexane very easily. H OH Ts-CI,py 0- CHs LiAH Ts or Tosyl- cyclohexyl tosylate ChlI Reacns of Alcohols (landscape) Page 6
Ch11 Reacns of Alcohols (landscape) Page 6 One such conversion involves tosyl chloride, and the formation of a tosylate. (These compounds undergo substitution and elimination very easily, often more reactive than alkyl halides). Cyclohexanol will not reduce with LiAlH4, but the corresponding tosylate reduces to cyclohexane very easily. H OH H O S O O CH3 Ts or TosylTs-Cl, py cyclohexyl tosylate H H LiAlH4
Tosylate Esters C R-0: -0- CH3 pyridine p-toluenesulfonyl chloride ROTs,a tosylate ester TsCI,"tosyl chloride" Tosylate esters(tosylates)are typically formed from alcohols with reaction with Ts-Cl and pyridine(py). Tosylate groups undergo a variety of S2 reactions. CHCH2 S2 CH2CH3 C -Ts I一C H H +:0Ts iodide CH CH tosylate ion (S)-2-butyl tosylate (R)-2-butyl iodide The tosylate is such a good leaving group because it is a stable anion. ChlI Reacns of Alcohols (landscape) Page 7
Ch11 Reacns of Alcohols (landscape) Page 7 Tosylate Esters Tosylate esters (tosylates) are typically formed from alcohols with reaction with Ts-Cl and pyridine (py). Tosylate groups undergo a variety of SN2 reactions. The tosylate is such a good leaving group because it is a stable anion
The tosylate is such a good leaving group because it is a stable anion -OTs CH. CH← tosylate ion resonance-stabilizedanion 3 Pewon Edicon inc Common SN2 transformations of Tosylates: R-OTs O-H R-OH "C≡N R-CN Br R-Br R-O R-OR' :NHg R-NH2 LiAH4 R-H Ch!I Reacns of Alcohols (landscape) Page 8
Ch11 Reacns of Alcohols (landscape) Page 8 The tosylate is such a good leaving group because it is a stable anion. Common SN2 transformations of Tosylates: R OTs -O H - C N R' O - Br - :NH3 LiAlH4 R-OH R-CN R-Br R-OR' R-NH2 R-H