(+)-brasiliquinone C 在
potassium carbonate 、 magnesium iodide 作用下,
以
苯 为溶剂,
反应 25.0h,
以70%的产率得到Brasiliquinone B
参考文献:
名称:
对苯二酚-甲硅烷基烯醇醚杂化物的氧化环化不对称全合成巴西硅醌 B 和 C
摘要:
完成了角环素类抗生素( S )-巴西醌B和C的不对称全合成。苯并[ a ]蒽醌核心是通过对苯二酚-甲硅烷基烯醇醚杂化物的氧化环化构建的。将所得五环缩醛转化为甲硅烷基烯醇醚,经多步转化(包括脱氢、去甲硅烷化和脱缩醛化以及对苯二酚氧化)后,将其用 Pd(II)/O 2处理得到巴西硅醌 C。基于与合成产物的立体化学相关性,证实了天然巴西醌的 ( S )-构型。
Three new cytotoxic benz[a]anthraquinones with an ethyl group at C-3, brasiliquinones A-C 1-3, have been isolated from the actinomycete Nocardia brasiliensis IFM 0089, and their structures elucidated on the basis of spectroscopic data and by chemical means, Brasiliquinone A 1 is the first benz[a]anthraquinone possessing ristosamine as an O-glycoside moiety, while brasiliquinones B 2 and C 3 correspond to the aglycone of 1 and the 8-O-methyl derivative of 2, respectively.
Asymmetric Total Synthesis of Brasiliquinones B and C via Oxidative Cyclization of a Hydroquinone-Silyl Enol Ether Hybrid
作者:Hiroki Miyake、Ryo Nakajima、Takuya Kumamoto
DOI:10.1021/acs.joc.2c01653
日期:2022.9.16
The asymmetric total synthesis of angucycline antibiotics (S)-brasiliquinones B and C was accomplished. The benz[a]anthraquinone core was constructed via oxidative cyclization of a hydroquinone-silyl enol ether hybrid. The resultant pentacyclic acetal was converted to the silyl enol ether, which was treated with Pd(II)/O2 to afford brasiliquinone C, after multistep conversion including dehydrogenation
完成了角环素类抗生素( S )-巴西醌B和C的不对称全合成。苯并[ a ]蒽醌核心是通过对苯二酚-甲硅烷基烯醇醚杂化物的氧化环化构建的。将所得五环缩醛转化为甲硅烷基烯醇醚,经多步转化(包括脱氢、去甲硅烷化和脱缩醛化以及对苯二酚氧化)后,将其用 Pd(II)/O 2处理得到巴西硅醌 C。基于与合成产物的立体化学相关性,证实了天然巴西醌的 ( S )-构型。