123932-68-3Relevant articles and documents
New polyacetylenes, DGAT inhibitors from the roots of Panax ginseng
Lee, Seung Woong,Kim, Koanhoi,Rho, Mun-Chual,Chung, Mi Yeon,Kim, Young Ho,Lee, Sangku,Lee, Hyun Sun,Kim, Young Kook
, p. 197 - 200 (2004)
The petroleum ether extract of Panax ginseng showed a significant inhibition of the diacylglycerol acyltransferase (DGAT) enzyme from rat liver microsomes. Bioactivity-guided fractionation led to the isolation of two new polyacetylenic compounds, (9R,10S)-epoxyheptadecan-4,6-diyn-3-one (1) and 1-methoxy-(9R,10S)-epoxyheptadecan-4,6-diyn-3-one (2). Their chemical structures were elucidated on the basis of spectroscopic evidence and asymmetric synthesis. IC50 values of 9 μg/mL (1) and 32 μg/ml (2) were obtained.
Total synthesis and absolute stereochemistry of (9R,10S)-epoxyheptadecan-4, 6-diyn-3-one, a diacylglycerol acyltransferase inhibitor from Panax ginseng
Oh, Jung-Hoon,Lee, Hyun Sun,Rho, Mun-Chual,Kim, Young Kook,Lee, Hyeong Kyu,Lee, Woo Song,Kim, Jae Nyoung,Lee, Sangku,Jung, Sang-Hun
, p. 7077 - 7079 (2007/10/03)
Asymmetric synthesis of four possible stereoisomers of (9,10)- epoxyheptadecan-4,6-diyn-3-one was accomplished, and the absolute configuration of the naturally occurring (9R,10S)-epoxyheptadecan-4,6-diyn-3-one (1) was elucidated.
Catalytic Asymmetric Epoxidation and Kinetic Resolution: Modified Procedures Including in Situ Derivatization
Gao, Yun,Hanson, Robert M.,Klunder, Janice M.,Ko, Soo Y.,Masamune, Hiroko,Sharpless, K. Barry
, p. 5765 - 5780 (2007/10/02)
The use of 3A or 4A molecular sieves ( zeoiltes ) substantially increases the scope of the titanium(IV)-catalyzed asymmetric epoxidation of primary allylic alcohols.Whereas without molecular sieves epoxidations employing only 5 to 10 mol percent Ti(O-i-Pr)4 generally led to low conversion or low enantioselectivity, in the presence of molecular sieves such reactions generally led to high conversion (>95percent) and high enantioselectivity (90-95percent ee).The epoxidations of 20 primary allylic alcohols are described.Especially noteworthy are the epoxidations of cinnamyl alcohol, 2-tetradecyl-2-propen-1-ol, allyl alcohol, and crotyl alcohol-compounds which heretofore had been considered difficult substrates for asymmetric epoxidation.In the case of allylic alcohol, the use of cumene hydroperoxide substantially increases both the reaction rate and the conversion, even in the absence of molecular sieves.In general, enantioselectivities are slightly depressed (by 1-5percent ee) relative to reactions employing 50-100 mol percent Ti(O-i-Pr)4.The epoxidation of low molecular weight allylic alcohols is especially facilitated and, in conjuction with in situ derivatization, provides for the synthesis of many epoxy alcohol synthons which were previously difficult to obtain.The kinetic resolution of four secondary allylic alcohols with 10 mol percent Ti(O-i-Pr)4 is also described.The role of molecular sieves in the reaction and the effects of variation in reaction stoichiometry, oxidant, and tartrate are discussed.
