D. A. Evans, N. Finney Hydrazone Transformations-2 Chem 206 The Wharton Rearrangement 1. LAH Me W-K 2HH20 CHO CO2CH3 L H. Zalkow, NN. Girotra J.Org. Chem. 1964, 29, 1299 Elimination of (-Lea oups This example illustrates the 2 possible modes for the decomposition of A. BrcH2、Me BrcH2、Me H Kishner CHOH.△ Me a A-C(+) adical -B D.H. Gusyafson, W. F. Erman J. Org. Chem. 1965, 30, 1665 G. Stork et al. JACS 1977. 99. 7067 Some procedural improvements ca.40%,32pa KDA, Ko Bu, etc M Kupchan JACS 1967, 89, 6327 For stable hydrazones, strongly basic conditions favor the ionic pathway C Dupuy, J. L Luche Tetrahedron Lett. 1989, 44, 3437Me Me O O CO2CH3 O O O Me O O Me O Me BrCH2 Me Me H N N H Br Me -B Me Me CHO –N2 –HBr BrCH2 Me NNH Me W-K –N2 Me Me CH2 O O Me O O Me H A C(–) Me Me Me Me Me OH Me Me Me Me Me O Me O Me Me Me Me O O N2H4 CH3OH, D R R R NNH R O O N Me Me Me Me H N H A C(+) NH2NH2 •H2O N2H4 Me Me Me Me OH :B OH H R R R R OH Me Me Me Me –N2 Me Me Me Me OH N NH OH Me Me Me Me A Hydrazone Transformations-2 Chem 206 L. H. Zalkow, N. N. Girotra J. Org. Chem. 1964, 29, 1299. 1. LAH 2. H+ /H2O 3. CrO3 Elimination of -Leaving Groups D. H. Gusyafson, W. F. Erman J. Org. Chem. 1965, 30, 1665. N2H4, H+ Wolff￾Kishner Wolff￾Kishner S. M. Kupchan JACS 1967, 89, 6327. ca. 40%, 3:2 b:a 76% Some procedural improvements: G. Stork et al. JACS 1977, 99, 7067. 20% For stable hydrazones, strongly basic conditions favor the ionic pathway. –N2, H• • This example illustrates the 2 possible modes for the decomposition of A. 30% The Wharton Rearrangement C. Dupuy, J. L. Luche Tetrahedron Lett. 1989, 44, 3437. KDA, KOtBu, etc. D. A. Evans, N. Finney radical pathway polar pathway