Byron, D. J.; Matharu, A. S.; Rees, M., Molecular Crystals and Liquid Crystals Science and Technology, Section A: Molecular Crystals and Liquid Crystals, 1995, vol. 258, p. 229 - 238
α'β-Elimination and wittig rearrangement of the carbanion from benzyl cyclooctyl ether
作者:Hugues d'Orchymont、Maurice P. Goeldner、Jean-François Biellmann
DOI:10.1016/s0040-4039(00)87201-9
日期:1982.1
Beside the Wittig rearrangement and the migration of the cyclooctyl radical to the para position, the title carbanion gives rise to an elimination in a syn process.
除了维蒂希重排和环辛基自由基向对位的迁移外,标题碳负离子还导致在合成过程中被消除。
Preparation of amino acids from unsaturated hydantoins
申请人:STAUFFER CHEMICAL COMPANY
公开号:EP0177072A2
公开(公告)日:1986-04-09
Amino acids can be easily prepared by reducing unsaturated hydantoins to the corresponding saturated hydantoins by hydrogenating the unsaturated hydantoin using either Raney Nickel catalyst in the presence of more than a stoichiometric amount of caustic or by using zinc and hydrochloric acid followed by hydrolyzing the resultant composition with at least 3 molar equivalents of an alkali metal hydroxide to produce a racemate of an alpha amino acid. The amino acid in suitable derivative form can then be resolved particularly using a two-phase solvent system. The residual isomer of the amino acid remaining after the resolution process can then be racemized using either pyridoxal-5-phosphate or an aliphatic acid in combination with an aldehyde or a ketone. By these procedures, it is possible to obtain high yields of amino acids.
There is disclosed a number of processes for the promotion of the Raney Nickel catalyzed hydrogenation of carbon-carbon double bonds. (a) One process uses tertiary amines to promote the Raney Nickel catalyzed hydrogenation. (b) Another process uses acetylene and acetylene derivatives to promote the Raney Nickel catalyzed hydrogenation. The promotion of Raney Nickel catalyst is particularly suited for the reduction of unsaturated hydantoins to saturated hydantoins and also for the reduction of cyclic and acyclic olefins and diolefins to the corresponding cyclic and acyclic alkanes.