Henbest modification

Table 3 Wolff-Kishner Reduction of Carbonyl Hydrazones Using the Henbest Modification...

The method employed by Law, et al. to obtain Ad-disubstituted ISQs [87] was a modification of the approaches of Henbest [88], Huffman [89] and Nelson [90] (Scheme 8). Epoxidation of commercially available methyl-3-cyclohexene-1-carboxylate (80) with m-CPBA yielded a mixture of epoxides (81a and 81b), which were then opened with various amines producing the isomeric amino alcohols (82a and 82b). Only isomer 82a is capable of undergoing cyclization to the... 

Homogeneous hydrogenation catalysts. Birch and Williamson have reviewed these catalysts (344 references). In addition to Wilkinson s catalyst (probably the most widely used), [RhCl(py)2(DMF)2BH4]CI, lrCl(CO)[P(C6H5)3]2, K3[Co(CN)s], Co2(CO)s, Henbest s catalyst, and soluble Ziegler catalysts are covered in detail. The authors conclude that at the present time many of the catalysts are not particularly useful for synthesis, probably because most of the investigations have been directed at mode of action and modifications of the catalysts. 

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