Phytochemical investigation of the dried leaves of Jasminum officinale var. grandiflorum has led to the isolation of two new secoiridoid glucosides, (2"R)-2"-methoxyoleuropein and (2"S)-2"-methoxyoleuropein, together with four known secoiridoid glucosides, oleuropein, ligstroside, demethyloleuropein and oleoside dimethyl ester, a lignan, (-)-olivil and p-hydroxyphenethyl alcohol. The structures of the new compounds were elucidated from chemical and spectroscopic evidence.
通过对欧鼠李变种(Jasminum officinale var. grandiflorum)的干燥叶片进行植物化学研究,分离出了两种新的仲呋喃糖苷((2 "R)-2"-甲氧基欧鼠李素和(2 "S)-2"-甲氧基欧鼠李素),以及四种已知的仲呋喃糖苷(油菜素、ligstroside、去甲基油菜素和油菜苷二甲酯)、一种木质素、(-)-醇和对羟基苯乙醇。新化合物的结构是通过化学和光谱证据阐明的。
Synthesis of pulvinones via tandem Dieckmann condensation–alkoxide β-elimination
作者:Brice Nadal、Julien Rouleau、Hélène Besnard、Pierre Thuéry、Thierry Le Gall
DOI:10.1016/j.tet.2011.02.011
日期:2011.4
A series of pulvinones were prepared in three steps from a common precursor, methyl 3-phenylglycidate. This compound was readily converted to several diesters containing an ether function. Then, treatment of these compounds with lithium hexamethyldisilazide afforded the corresponding pulvinones, via tandem Dieckmann condensation-alkoxide beta-elimination. The use of a 2,2,2-trifluoroethyl ether instead of a methyl ether facilitated the beta-elimination and led to better yields of product. (C) 2011 Elsevier Ltd. All rights reserved.