Synthetic studies of the (7''R)-8-[1-(4'-hydroxy-3'-methoxyphenyl)prop-2-en-1-yl]galangin

• Main Authors: Yi-Chih Lu, 呂益誌
• Other Authors: Yean-Jang Lee
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/92332011961472886474

碩士 === 國立彰化師範大學 === 化學系 === 101 === (7''R)-8-[1-(4'-Hydroxy-3'-methoxyphenyl)prop-2-en-1-yl]galangin, a new flavonoid isolated from Mexican propolis in 2010, displays preferential cytotoxicity against PANC-1 cells of human pancreatic cell line. First, the preparation of 8-bromo galangin was begun from the commercially available phloroglucinol. The phloroglucinol was converted by methylation and acetylation reactions to give dimethoxyphenyl acetate in two steps overall 49% yield. The dimethoxyphenyl acetate was transformed by Fries rearrangement in presence of AlCl3 to give acetophenone in 58% yield. Continually, to couple acetophenone and benzaldehyde with aldol condensation was performed to afford chalcone. The chalcone was converted to galangin by Algar-Flynn-Oyamada reactiont in existence of 20% NaOH and H2O2 in MeOH. However, it’s failed to get the desired galangin. Alternatively, the chrysin was employed by hydroxylation and bromination reactions to obtain the 8-bromo galangin in four steps overall 32% yield. On the other hand, the propiophenone was provided by Friedel-Crafts reaction of 2-methoxyphenol and propionic acid under BF3．OEt2 in 69% yield. In addition, propiophenone was converted to bromopropene under the presence of PBr3/ DMF in 70% yield, and then followed by SeO2 oxidation to give alcohol compound. The corresponding α-vinylstannane was successfully prepared in existence of t-BuLi/SnBu3Cl in moderate 59% yield. Finally, 8-bromo galangin and α-vinylstannane were transformed by Stille coupling reaction to afford the precursor (7''R)-8-[1-(4'-Hydroxy-3'-methoxyphenyl)prop-2-en-1-yl]galangin in 36% yield.