517-88-4Relevant articles and documents
High performance liquid chromatography resolution method of alkannin raceme and naphthazarin parent nucleus hydroxyl methylated carbonyl oxime derivative of alkannin raceme
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Paragraph 0036-0045, (2021/04/17)
The invention discloses a high performance liquid chromatography resolution method of alkannin raceme and naphthazarin parent nucleus hydroxyl methylated carbonyl oxime derivatives thereof, which comprises the following steps: using high performance liquid chromatography, using amylose-tris [(S)-alpha-methyl benzyl carbamate] as a filler and an n-hexane-isopropanol mixed solvent as a mobile phase, separating high-purity R-(+)-alkannin from an alkannin raceme, separating high-purity S-(+)-alkannin naphthazarin parent nucleus hydroxyl methylated carbonyl oxime derivatives from an alkannin raceme naphthazarin parent nucleus hydroxyl methylated carbonyl oxime derivative, and combining a certain separation and purification means. Therefore, the production efficiency of R-(+)- alkannin is improved, and the efficiency of producing the optically pure alkannin naphthazarin parent nucleus hydroxyl methylated carbonyl oxime derivative by using an intermediate resolution method is improved.
An efficient multigram synthesis of alkannin and shikonin
Wang, Rubing,Zhou, Shanshan,Jiang, Hudagula,Zheng, Xiaogang,Zhou, Wen,Li, Shaoshun
, p. 1373 - 1379 (2012/04/04)
The concise and efficient total syntheses of alkannin (1) and shikonin (2), based on the resolution of a key acid intermediate, are achieved with excellent enantiomeric excesses and high overall yields (99 % ee, 15.6 % for 1 and 99.8 % ee, 11.9 % for 2). The key steps of the synthetic strategy involve the convenient synthesis and separation of a pair of amide diastereoisomers and the mild hydrolysis of the amide to remove the amine chiral auxiliary, together with an efficient deprotection sequence of the methyl protecting groups. The concise and efficient syntheses of alkannin and shikonin remained elusive until recently. We have developed a new method of resolution for achieving the syntheses of alkannin (1) and shikonin (2) in excellentenantiomeric excesses (≥ 99 % ee for 1 and ≥ 99.8 % ee for 2) and high yields (27.5 %) with low cost, which is practical for use in large-scale preparation. Copyright
An efficient improvement on total synthesis of shikonin
Rao, Zhen,Zhou, Wen,Peng, Ying,Li, Shao-Shun
experimental part, p. 236 - 237 (2010/08/06)
The problem associated with electrolytic deprotection, which is a concern in the total synthesis of shikonin, is solved by the addition of Cu2+ to the electrolysis system. The improvement has three advantages: first, it practically increased the yield from 40 to 85%; second, the isolation of shikonin became much easier. Third, the reaction time was significantly shortened.
