887278-75-3Relevant articles and documents
Synthesis and analysis of the all-(S) side chain of phosphomycoketides: A test of NMR predictions for saturated oligoisoprenoid stereoisomers
Buter, Jeffrey,Yeh, Edmund A.-H.,Budavich, Owen W.,Damodaran, Krishnan,Minnaard, Adriaan J.,Curran, Dennis P.
supporting information, p. 4913 - 4918 (2013/07/05)
(4S,8S,12S,16S,20S)-Pentamethylheptacosan-1-ol has been synthesized and analyzed by resolution-enhanced NMR spectroscopy with the aid of a recent set predicted spectra of all its stereoisomers. The configuration was confirmed, but isomer purity of the sample (~70%) was lower than expected. A truncated analogue, (2S,6S,10S,14S)-2,6,10,14-tetramethylhenicosan-1-ol TBDPS ether, was prepared from a late stage synthetic intermediate. Analysis of its spectra confirmed the configuration and showed that the sample was isomerically pure. The results suggest that a late-stage epimerization, not a failure of an asymmetric synthesis step, caused the formation of minor stereoisomers in the sample of pentamethylheptacosan-1-ol. The study shows the value of the predicted set of oligoisoprenoid spectra and further extends the predictive model to a new subclass of compounds.
Total synthesis of enantiopure β-D-mannosyl phosphomycoketides from Mycobacterium tuberculosis
Van Summeren, Ruben P.,Moody, D. Branch,Feringa, Ben L.,Minnaard, Adriaan J.
, p. 4546 - 4547 (2007/10/03)
The first stereoselective total synthesis of a β-d-mannosyl phosphomycoketide is reported. To introduce the stereogenic centers in the chain, three linear chiral building blocks were prepared using two different asymmetric catalytic conjugate addition protocols. Coupling of the various linear fragments was affected using a Julia-Kocienski sequence. This approach constitutes a general and convergent method for the construction of saturated oligoisoprenoid chains of any length and stereochemistry. In addition, an alternative approach for the formation of the difficult β-mannosyl phosphate linkage was shown to be successful. Biological evalutation of the all-S compound revealed that its antigenic potency for T cells is identical to that of the natural product. This result implies that the fine structure of the lipid part has a strong influence on biological activity and that the T cell response is discriminating between different stereoisomers. Copyright