70311-20-5Relevant articles and documents
Asymmetric total synthesis of dihydroisocoumarins: 6-methoxymellein, kigelin and fusarentin 6, 7 dimethyl ether by employing proline catalysed asymmetric α-aminoxylation
Mane, Baliram B.,Markad, Sachin B.,Waghmode, Suresh B.
, (2020/10/19)
A concise asymmetric total synthesis of dihydroisocoumarins such as 6-methoxymellein, kigelin and fusarentin 6,7-dimethyl ether in high enantiopurity have been achieved from non-chiral aldehydes by employing proline catalysed asymmetric α-aminoxylation reaction. The required stereochemistry of hydroxyl group have been generated by alternating L or D proline as a organocatalyst in α-aminoxylation step and lactone ring is assembled by oxa-Pictet-Spengler cyclisation reaction as the key steps.
Highly trans-Selective Arylation of Achmatowicz Rearrangement Products by Reductive γ-Deoxygenation and Heck-Matsuda Reaction: Asymmetric Total Synthesis of (-)-Musellarins A-C and Their Analogues
Li, Zhilong,Ip, Fanny C. F.,Ip, Nancy Y.,Tong, Rongbiao
supporting information, p. 11152 - 11157 (2015/11/10)
Fully functionalized pyranuloses derived from Achmatowicz rearrangement (AR) are versatile building blocks in organic synthesis. However, access to trans-2,6-dihydropyrans from pyranuloses remains underexplored. Herein, we report a new two-step trans arylation of AR products to access 2,6-trans-dihydropyranones. This new trans-arylation method built on numerous plausible, but unsuccessful, direct arylation reactions, including Ferrier-type and Tsuji-Trost-type reactions, was finally enabled by an unprecedented, highly regioselective γ-deoxygenation of AR products by using Zn/HOAc and a diastereoselective Heck-Matsuda coupling. The synthetic utility of the reaction was demonstrated in the first asymmetric total synthesis of (-)-musellarins A-C and 12 analogues in 11-12 steps. The brevity and efficiency of our synthetic route permitted preparation of enantiomerically pure musellarins and analogues (>20 mg) for preliminary cytotoxicity evaluation, which led us to identify two analogues with three-to-six times greater potency than the musellarins as promising new leads. O leaves, Ar comes: A highly regio- and diastereoselective trans-arylation of Achmatowicz rearrangement products by an unprecedented Zn-mediated reductive γ-deoxygenation and Heck-Matsuda reaction was developed for the efficient synthesis of trans-2-aryl-6-alkyl dihydropyranones (see scheme: L.A.=Lewis acid). The synthetic utility of this new method was further demonstrated in the first asymmetric total synthesis of (-)-musellarins A-C and 12 analogues in 11-12 steps.
Synthesis of salidroside analogues and their ability of DPPH radical scavenging activity
Zheng, Cheng,Guo, Yibing,Meng, Ying,Dou, Sufeng,Shao, Jian,Yang, Yumin
, p. 654 - 664 (2013/07/11)
Salidroside is a phenylpropanoid glycoside isolated from Rhodiolarosea L., a traditional Chinese medicinal plant, and has displayed a broad spectrum of pharmacological properties. In this paper, about 22 novel glycosides have been synthesized and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenge activity of each glycoside has been evaluated. 2-(3,4,5-Trihydroxyphenyl)ethyl β-D-galactopyranoside and 3-(3,4,5-trihydroxyphenyl)propyl β-D-glucopyranoside exhibit significant activity prior to salidroside and Vitamin C with EC50 values of 35.85 μM and 36.71 μM, respectively. The results indicate that the phenolic hydroxyl group of these compounds is important for radical scavenging activity and phenyl ring substitution by electron-donating substituents lead to increased antioxidant activity.
