D. A. Evans Hydrazone Transformations-4 Chem 206 The Eschenmoser-Tanabe Fragmentation Tosylhydrazone Reductions: The Alkene Walk TsNHNH2, ACOH N NNHTS base H C. Djerassi, et al. JACS 1976, 98, 2275 A Eschenmoser. et al. Helv. Chem. Acta 1967. 50. 708. This has been developed into a reliable reduction N A Eschenmoser, et al. Hel. Chem. Acta 1967. 50. 2108 16 cases reported: Hutchins, et al. JOC 1975, 40, 92N N H NaBD3CN Me TsNHN N N H H Ts NaBH3CN N N H Ts H H - + CH3 O O O H N N Ts CH3 O O CH3 Ph N NH2 O Ph N N H CH3 –N2 CH3 N O N Ph H N O CH3 N H Ts H CH3 O Ph CH2 H3C CHO D O S O Ar Me NNHTs Me Me Me Me O Me O Me Me H D Me H Me Me Me Me Hydrazone Transformations-4 Chem 206 + + + 94% HOAc Et2O, 0°C A. Eschenmoser, et al. Helv. Chem. Acta 1967, 50, 708. TsNHNH2, AcOH + The Eschenmoser–Tanabe Fragmentation CH2Cl2, RT A. Eschenmoser, et al. Helv. Chem. Acta 1967, 50, 2108. : + 68% D. A. Evans Tosylhydrazone Reductions: The Alkene Walk C. Djerassi, et al. JACS 1976, 98, 2275. 16 cases reported: Hutchins, et al. JOC 1975, 40, 923 84% 81% This has been developed into a reliable reduction base