Synthesis of Allyl- and Prenylcoumarins via Microwave-Promoted Tandem Claisen Rearrangement/Wittig Olefination
作者:Bernd Schmidt、Martin Riemer
DOI:10.1055/s-0035-1560501
日期:——
sequence of Claisenrearrangement, carbonyl olefination, and cyclization upon microwave irradiation in the presence of a stabilized ylide. The products are multiply substituted 6- or 8-allylated or prenylated coumarins (2H-chromen-2-ones). Allyl, dimethylallyl, crotyl, and prenyl ethers of various aromatic ortho-hydroxy carbonyl compounds undergo a tandem sequence of Claisenrearrangement, carbonyl olefination
摘要 各种芳族邻羟基羰基化合物的烯丙基,二甲基烯丙基,巴豆基和异戊烯基醚在稳定的内酯存在下进行微波辐射后,会经历克莱森重排,羰基烯烃化和环化的串联序列。产物是被多重取代的6-或8-烯丙基化或烯丙基化的香豆素(2 H -chromen-2-ones)。 各种芳族邻羟基羰基化合物的烯丙基,二甲基烯丙基,巴豆基和异戊烯基醚在稳定的内酯存在下进行微波辐射后,会经历克莱森重排,羰基烯烃化和环化的串联序列。产物是被多重取代的6-或8-烯丙基化或烯丙基化的香豆素(2 H -chromen-2-ones)。
Microwave-Assisted Synthesis of Phenylpropanoids and Coumarins: Total Synthesis of Osthol
A method was developed for the microwave-assisted one-pot synthesis of phenylpropanoids, monolignols, and coumarins. The chosen reaction conditions determine whether a cinnamic acid or coumarin derivative is produced. The optimized reaction conditions were also applied to the synthesis of osthol (13) and several other natural products.
Polyphosphoric acid-promoted synthesis of coumarins lacking substituents at positions 3 and 4
作者:Li-Shou Yang、Yu Wang、En-Hua Wang、Jan Yang、Xiong Pan、Xiu Liao、Xiao-Sheng Yang
DOI:10.1080/00397911.2020.1792498
日期:2020.10.17
Abstract Coumarins have recently emerged as a hot topic of research due to their diverse pharmacological properties. This work described a method for the synthesis of 3,4-diunsubstitutedcoumarins promoted by polyphosphoric acid (PPA) from salicylaldehydes and acetic anhydride. Various coumarins were produced in good to excellent yields. Graphical Abstract