Hydroxy elimination

Rearrangement of Hydroperoxides C-Alkyl- O-hydroxy-elimin ation... 

Decarboxylation of (3-Hydroxy Carboxylic Acids and of (3-Lactones Carboxy-hydroxy-elimination... 

Dehydration of Aldoximes and Similar Compounds C-Hydro-ZV-hydroxy-elimination... 

Unexpectedly, norbornene derivatives can undergo a novel cyclopropana-tion reaction with propargyl alcohol in the presence of cationic [(/f-Cp)(CH3CN)3Ru]+X catalysts, which have an electron-withdrawing substituent on the Cp ligand. Cyclopropanation products, exo-acetyltricyclooctanes, were obtained in good yields [50] (Eq. 37). The reaction has been shown not to involve the expected allenylidene intermediate but rather to lead to a ruthena-cycle intermediate and to a /i-hydroxy elimination. 

Fig. 2-34. Stopping reaction. 1 —>2, 1,2-Enediol formation 2 — 3, j3-hydroxy elimination 3 —> 4, tautomerization 4 —> 5, benzilic acid rearrangement leading to a glucometasaccharinic acid end group, (cf. Fig. 2-33.)...

The 4-O-methylglucuronic acid groups prevent the peeling of xylan chains at lower temperatures (< 100°C) but they offer only a partial protection at higher temperatures. Since the 4-O-methylglucuronic acid groups are bound to the C-2 position in the xylose units, no conversion of this carbon atom to a carbonyl group can take place. Instead, HO-3 is eliminated directly (/8-hydroxy elimination). 

Dialkylaminoalkyl-halo-elimination, and so on Hydroxyalkyl-hydroxy-elimination... 

C-Hydro-A-hydroxy-elimination C-Acyl-A-hydroxy-elimination... 

Scheme 57. Heterocyclization of Alkenylamines and Alcohols via (a) Cyclization—/ -Hydride Elimination, (b) Cyclization—/ -Hydroxy Elimination, (c) Cyclization—Acetalization, (d) Cyclocarbonylation, and (e) Cyclization—Carbonylative Esterification...

Y. Sorek, H. Cohen, and D. Meyerstein, Kinetics of the 8-Hydroxy Elimination Reactions from the Protoporphyrin Iron(III)-CHRCH20H Complexes in Aqueous Solutions. A Pulse Radiolysis Study, J. Chem. Soc., Faraday Trans. 1, 82 (1986) 3431. 

---