157810-31-6Relevant articles and documents
Formation of substituted tetrahydropyrans through oxetane ring opening: Application to the synthesis of C1-C17 fragment of salinomycin
Yadav,Singh, Vinay K.,Srihari
, p. 836 - 839 (2014)
The stereoselective synthesis of C1-C17 fragment of salinomycin is achieved. The strategy employs a desymmetrization approach and utilizes an intramolecular oxetane opening reaction with O-nucleophile to result in the tetrahydropyran skeleton as the key s
Absolute stereochemistry of TT-1 (rasfonin), an α-pyrone-containing natural product from a fungus, Trichurus terrophilus
Akiyama, Kohki,Kawamoto, Souichi,Fujimoto, Haruhiro,Ishibashi, Masami
, p. 8427 - 8431 (2007/10/03)
The absolute stereochemistry of TT-1 (1=rasfonin), an α -pyrone-containing natural product from a Fungi Imperfecti, Trichurus terrophilus, was determined as 5R,6R,7S,9R, and 6′S on the basis of synthesis of diastereomers of two fragments of 1 in optically
Synthetic routes to the stereoisomers of 2,4-dimethylpentane-1,5-diol derivatives
Mas, Gemma,González, Llu?sa,Vilarrasa, Jaume
, p. 8805 - 8809 (2007/10/03)
Five different routes to every stereoisomer of non-symmetric derivatives of 2,4-dimethylpentanedioic acid and/or of O-monoprotected 2,4-dimethylpentane- 1,5-diols, which are common building blocks for the total synthesis of many polypropionates, have been investigated. Alkylation of the lithium enolate of N-propanoylpseudoephedrine turned out to be the most appropriate method, in connection with the synthesis of fragment C1-C5 of amphidinolide K.
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
Siloxanes: Versatile Templates for Acyclic Stereocontrol. Synthesis of the C27-C33 Segment of Rapamycin
Hale, Michael R.,Hoveyda, Amir H.
, p. 1643 - 1645 (2007/10/02)
Five-membered siloxane rings may be employed to relay asymmetry along an acyclic chain in an efficient manner.Application of this method to the synthesis of the C27-C33 segment of the immunosuppressant rapamycin is reported.
A Highly Convergent Total Synthesis of (+)-Myxovirescine M2
Seebach, Dieter,Maestro, Miguel A.,Sefkow, Michael,Neidlein, Axel,Sternfeld, Francine,et al.
, p. 2112 - 2118 (2007/10/02)
The antibiotic myxovirescine M2 was synthesized from seven building blocks (1-7, Scheme 1), with the following chiral starting materials being employed : (S)-malic acid, (+)-D-ribonolactone, (S)-2-(hydroxymethyl)butanoate, and (2R,4S)-5-hydroxy