Reductions epoxides

Though the usual product of epoxide reductions is the alcohol (10-85), epoxides are reduced all the way to the alkane by titanocene dichloride and Et3SiH-BH3. ... 

For a review of epoxide reduction with Bll<. see Cragg, Organoboranes in Organic Synthesis Marcel Dekkcr New York. 1973. pp. 345-348. See also Yamamoto Toi Sonoda Murahashi J. Chem. Soc., Chem. Commun. 1976, 672. 

A recent paper by Kwiatek and co-workers1891 discloses the use of a homogeneous catalysis system for the hydrogenation of epoxides. Reduction of cyclohexene oxide to cydohexanol, and of styrene oxide to 2-phenylethanol, was carried at atmospherio pressure, using Ks[Co(CN) ] to catalyze the reaction. 

Radical Epoxide Reduction Borane-free Two-step Synthesis of anti-Markownikow Alcohols from Alkenes... 

Transition metal nanoparticles supported on different substrates are used as catalysts for different reactions, such as hydrogenations and enantioselective-synthesis of organic compounds, oxidations and epoxidations, reduction, and decomposition [24,25], Among the supports that have been applied in the preparation of supported transition metal nanoparticles are active carbon, silica, titanium dioxide, and alumina. 

Give an explanation of the regioselectivity obtained in the epoxide reduction of step k. 

Give reasons for the regioselectivity observed in the epoxide reduction step u. 

Epoxide reduction with LiAlH (abnormal cis-3,4-epoxy-5-ols 4,5-diols) E. Glotter, Sk Greenfield and D. Lavie, Teimhedron Letters, No. 52 (1967) 5261. 

Conjugate reduction of unsaturated epoxides Reduction of 2 methyl-l,2-oxido-3-butene (I) with DIBAH in refluxing hexane results in highly stereoselective conjugate addition to give the Z alcohol (2) the E isomer (3) is a minor product. 

Reduction of (I) with DIBAH in THF leads mainly to the homoallylic alcohol (4) formed by direct, MarkownikoIT addition of the hydride to the epoxide. Reduction of (1) with lithium aluminum hydride gives exclusively the tertiary allylic alcohol (S). 

Two types of reductions of epoxides, reduction giving alcohols and deoxygenation to alkenes, are dealt with in this chapter, because of their wide applicability in organic synthesis. These reactions provide access to alcohols and to alkenes when combined with appropriate methods for the synthesis of the starting epoxides, but the two-step conversion of alkenes to alcohols via epoxides is the more important. 

The usual product of epoxide reductions is the alcohol, but epoxides are reduced... 

---