title: Selective methylation of kaempferol via benzylation and deacetylation of kaempferol acetates.
abstract: 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.
authors: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China ; Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China ; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Qinggang
authors: Q
authors: Mei
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors: Chun
authors: C
authors: Wang
authors: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China.
authors: Weicheng
authors: W
authors: Yuan
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
authors: Guolin
authors: G
authors: Zhang
keywords: benzylation; deacetylation; kaempferol; methylation; regioselectivity