69205-11-4Relevant academic research and scientific papers
Reduction of carbon-carbon double bonds using organocatalytically generated diimide
Smit, Christian,Fraaije, Marco W.,Minnaard, Adriaan J.
supporting information; experimental part, p. 9482 - 9485 (2009/04/06)
(Chemical Equation Presented) An efficient method has been developed for the reduction of carbon-carbon double bonds with diimide, catalytically generated in situ from hydrazine hydrate. The employed catalyst is prepared in one step from riboflavin (vitamin B2). Reactions are carried out in air and are a valuable alternative when metal-catalyzed hydrogenations are problematic.
BiBr3, an efficient catalyst for the benzylation of alcohols: 2-Phenyl- 2-propyl, a new benzyl-type protecting group
Boyer, Bernard,Keramane, El-Mehdi,Roque, Jean-Pierre,Pavia, André A.
, p. 2891 - 2894 (2007/10/03)
The benzylation of aliphatic alcohols with various benzylic alcohols has been achieved in the presence of BiBr3 under mild conditions. 2- Phenylpropan-2-ol proved to be the most efficient and can be considered as a novel protecting group. (C) 2000 Elsevier Science Ltd.
Total Synthesis of Myxovirescins, 2. Assembly of the "Northwestern" Part
Sefkow, Michael,Neidlein, Axel,Sommerfeld, Thimo,Sternfeld, Francine,Maestro, Miguel A.,Seebach, Dieter
, p. 719 - 730 (2007/10/02)
The part of the target molecules myxovirescins A and M containing the atoms C(15)-C(28) is described in this paper (for retrosynthetic analysis see Scheme 1).There are three stereogenic centers which are incorporated by using (S)-2-hydroxymethyl-butanoic acid and the appropriate enantiopure diastereoisomeric 2,4-dimethyl-glutaric acids as building blocks (Schemes 2-4).These are joined by the achiral unit 4-oxo-hex-5-enoic acid.The key steps of the assembly are a cuprate Michael addition (Scheme 5) and a nucleophilic addition of a Li derivative to an aldehyde (Scheme 6).In both cases the organometallic reagents are generated by I/Li exchange using two equiv. of tBuLi.The chiral building blocks are prepared by yeast reduction of ethyl 2-formyl-butanoate and by resolution of the 2,4-dimethyl-pentanedioic acid monomethyl ester with phenethylamine; both enantiomers derived from the meso-2,4-dimethyl-glutaric acid are converted to the same aldehyde (5a; "meso-trick", Schemes 3 and 4).The "northwestern" parts for the final synthesis are actually hydroxy sulfones (2 in Scheme 6), the termini of which are ready for Julia coupling and oxidation to a carboxylic acid group.The preparation of the intermediates on gram scales is described and all new compounds are fully characterized by their physical properties, by spectroscopy (IR, 1H- and 13C-NMR spectra) and by elemental analysis. - Key Words: Myxovirescins / Myxococcus virescens / Antibiotics / Macrolides / Lactones / Lactams / Iodine-lithium exchange / Michael additions
