First stereoselective total synthesis and anticancer activity of new amide alkaloids of roots of pepper
作者:Ch. Srinivas、Ch.N.S. Sai Pavan Kumar、B. China Raju、V. Jayathirtha Rao、V.G.M. Naidu、S. Ramakrishna、Prakash V. Diwan
DOI:10.1016/j.bmcl.2009.08.056
日期:2009.10
The first stereoselectivetotalsynthesis of new natural amide alkaloids 1–3 have been achieved from commercially available starting materials. Wittig olefination, Sharpless asymmetric dihydroxylation, epoxidation, a trans regioselective opening of 2,3-epoxy alcohol, Horner–Wadsworth–Emmons (HWE) olefination and amide coupling are the key steps. The amide alkaloids 1–3 are evaluated for their anticancer
The enantioselective synthesis of the four possible isomers of (E)-4,5-dihydroxydec-2-enal, a cytotoxic product formed in peroxidised liver microsomal lipids, is accomplished via a Sharpless AD reaction alone or associated as appropriate with a regioselective epimerisation of one of the introduced hydroxy groups. (C) 1997 Elsevier Science Ltd.
Synthesis and biological evaluation of truncated α-galactosylceramide derivatives focusing on cytokine induction profile
A series of truncated analogs of alpha-galactosylceramide with altered ceramide moiety was prepared, and evaluated for Th2-biased response in the context of IL-4/IFN-gamma ratio. Phytosphingosine-modified analogs including cyclic, aromatic and ethereal compounds as well as the C-glycoside analog of OCH (2) with their cytokine inducing profile are disclosed. (C) 2012 Elsevier Ltd. All rights reserved.
The first synthesis of all possible stereoisomers of the (E)-4,5-dihydroxydec-2-enal, in homochiral form
The first synthesis of the four possible isomers of (E)-4,5-dihydroxydec-2-enal, a cytotoxic product of microsomal lipid peroxidation, is accomplished starting with D- and L-arabinose, D-ribose and D-lyxose by an identical reaction sequence. Each pentose was diacetonised and subjected to a Wittig reaction for the introduction of a four carbon chain. A selective cleavage of the terminal isopropylidene acetal and the oxidation of the diolic system affords a noraldehyde which is treated with (formylmethylene)triphenylphosphorane to afford the target molecule after regeneration of the diolic system.
A concise synthesis of (3S,4S,5R)-1-(α-d-galactopyranosyl)-3-tetracosanoylamino-4,5-decanediol, a C-glycoside analogue of immunomodulating α-galactosylceramide OCH
A concise and convergent synthesis of the C-glycoside analogue 2b of immunomodulating alpha-galactosylceramide OCH 1b starting from readily available 2,3,4,6-tetra-O-bensyl-D-galactose 3 and L-arabinose 6 is described. The synthesis features the nucleophilic addition of an alpha-ethynyl sugar 5 to the phytosphingosine-precursor aldehyde 9 and would be applicable to a variety of C-glycoside analogues of interest. (c) 2005 Elsevier Ltd. All rights reserved.