Methylation of methyl α-d-hexopyranosides with diazo-methane in the presence of a small amount of water
作者:Yuko Inoue、Kinzo Nagasawa
DOI:10.1016/0008-6215(87)80024-1
日期:1987.11
Abstract The long-time reduction of methylα-d -gluco-, α-d -manno-, and α-d -galactopyranosides with excess diazomethane-diethyl ether at 25° in the presence of water gave all partially methylated methylα-d -hexopyranosides which differ in number and position of methyl substitution. The presence of electrolytes, such as potassium or sodium phosphate, in the reaction medium enhanced the degree of methylation
Regioselective alkylation via trialkylstannylation: Methyl α-d-glucopyranoside
作者:Tomoya Ogawa、Yukio Takahashi、Masanao Matsui
DOI:10.1016/s0008-6215(00)88063-5
日期:1982.4
Abstract Partial stannylation of methylα- d -glucopyranoside with (Bu 3 Sn) 2 O, and subsequent alkylation with benzyl bromide, allyl bromide, and trityl chloride, afforded the 2,6-disubstituted derivatives as one of the major products in each case.
A new triterpenoidal saponin, 3-O-[α-L-rhamnopyanosyl(1→2)-α-L-arabinopyranosyl(1→2)-β-D-glucuronopyranosyl]sophoradio (I), was isolated from the flowers of Pueraria lobata (WILLD.) OHWI (Leguminosae). Its structure was elucidated on the basis of chemical and physicochemical evidence. In addition, a known oligoglycoside kaikasaponin III (II) was isolated from both flowers and leaves of this plant, together with several known aromatic compounds.
从野葛(Pueraria lobata (WILLD.) OHWI)(豆科植物)的花中分离出一种新的三萜类皂甙--3-O-[α-L-rhamnopyanosyl(1→2)-α-L-arabinopyranosyl(1→2)-β-D-glucuronopyranosyl]sophoradio (I)。根据化学和物理化学证据阐明了其结构。此外,还从该植物的花和叶中分离出一种已知的低聚糖苷 kaikasaponin III (II),以及几种已知的芳香族化合物。
KINJO, JUN-EI;TAKESHITA, TAKASHI;ABE, YOKO;TERADA, NAOKO;YAMASHITA, HIROS+, CHEM. AND PHARM. BULL., 36,(1988) N 3, 1174-1179