基于 Stork-Danheiser 反应,开发了一种以收敛方式获取黄酮的新方法。通过这种方法,4-甲氧基香豆素可以在低温(-78 °C 至 -40 °C)下与有机锂反应,然后进行酸性处理,得到所需的黄酮,产率为 18-86%。该方法具有无过渡金属条件、起始原料易得、操作简单等特点。当需要快速生成 B 环黄酮衍生物时,它特别有效。
作者:Roger D. Waigh、Berhame M. Zerihun、Derek J. Maitland
DOI:10.1016/0031-9422(91)84149-m
日期:1991.1
Abstract The chloroform extract of the powdered whole root of Clutiaabyssinica has yielded a complex mixture of 5-methylcoumarins, of which 10 have been isolated in pure form and identified, mostly by NMR.
PHOTOCROSSLINKABLE POLYMER, INSULATING FILM, PLANARIZATION FILM, LYOPHILIC/LIQUID REPELLENT PATTERNED FILM, AND ORGANIC FIELD EFFECT TRANSISTOR DEVICE COMPRISING SAME
申请人:TOSOH CORPORATION
公开号:US20210135115A1
公开(公告)日:2021-05-06
Provided is a resin which is excellent in terms of solubility in common solvents, crosslinking temperature, time required for crosslinking, solvent resistance (cracking resistance), breakdown voltage, leakage current, solvent wettability, and planarity in cases where the resin is formed into a thin film. A resin which comprises repeating units represented by formula (1) and formula (2), and wherein the repeating unit represented by formula (2) is contained in an amount of 20% by mole or more relative to the total amount of the repeating units represented by formula (1) and formula (2).