- Selective methylation of kaempferol via benzylation and deacetylation of kaempferol acetates
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A strategy for selective mono-, di- and tri-O-methylation of kaempferol, predominantly on the basis of selective benzylation and controllable deacetylation of kaempferol acetates, was developed. From the selective deacetylation and benzylation of kaempferol tetraacetate (1), 3,4′,5,-tri-O-acetylkaempferol (2) and 7-O-benzyl-3,4′5,-tri-O-acetylkaempferol (8) were obtained, respectively. By controllable deacetylation and followed selective or direct methylation of these two intermediates, eight O-methylated kaempferols were prepared with 51-77% total yields from kaempferol.
- Mei, Qinggang,Wang, Chun,Yuan, Weicheng,Zhang, Guolin
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supporting information
p. 288 - 293
(2015/03/31)
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- Total synthesis of kaempferol and methylated kaempferol derivatives
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Kaempferol (1), a natural product from various plants, was synthesized in which the longest linear sequence is only seven steps in overall yields of 47% from commercially available 1,3,5-trimethoxybenzene (10). The methylated kaempferols 2-5 were also prepared by use of this concise synthetic methodology. The key transformations in this synthesis involved the I2 oxidative-promoting-cyclization and DDO oxidative hydroxylation. Several strategies to achieve 1 are provided.
- Lee, Yean-Jang,Wu, Tsao-Dong
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p. 201 - 206
(2007/10/03)
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