Zhou Tingting, Zheng Anquan, Zhang Wenge, Lu Xiuxiang, Chen Huiyu, Tan Haibo
Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China.
School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, People's Republic of China.
Org Biomol Chem. 2022 May 26;20(20):4096-4100. doi: 10.1039/d2ob00634k.
A two-step protecting-group-free protocol for the synthesis of 3'-hydroxy-5,7-dimethoxy-4-O-2'-cycloflavan (1) and concise total synthesis of 4'-hydroxy-5,7-dimethoxy-4-O-2'-cycloflavan (8) enabled by a PTSA triggered bioinspired olefin isomerization/hemiacetalization/dehydration/[3 + 3]-type cycloaddition cascade reaction are reported. The successful synthesis of cycloflavan 8 along with GIAO C NMR calculations of flavan-4-ol 9 and cycloflavan 8 indicated the misassignment of the flavonoid isolated previously and realized the revision of its actual structure.
报道了一种用于合成3'-羟基-5,7-二甲氧基-4-O-2'-环黄烷（1）的两步无保护基方案，以及通过对甲苯磺酸引发的仿生烯烃异构化/半缩醛化/脱水/[3 + 3]型环加成串联反应实现的4'-羟基-5,7-二甲氧基-4-O-2'-环黄烷（8）的简洁全合成。环黄烷8的成功合成以及黄烷-4-醇9和环黄烷8的GIAO C NMR计算表明了先前分离的黄酮类化合物的错误归属，并实现了其实际结构的修正。
