519002-37-0Relevant articles and documents
Synthesis of the pluramycins 2: Total synthesis and structure assignment of saptomycin B
Kitamura, Kei,Maezawa, Yoshihiko,Ando, Yoshio,Kusumi, Takenori,Matsumoto, Takashi,Suzuki, Keisuke
, p. 1262 - 1265 (2014/03/21)
A concise, highly convergent total synthesis of saptomycin B, a member of the pluramycin class of antitumor antibiotics, is reported. The target compound was assembled from four building blocks (a tricyclic platform, two sugars, and an alkynal) in 15% yield through 10 synthetic operations. The key steps included the regioselective installation of two amino sugars (l-vancosamine and d-angolosamine) on the tricycle and the efficient construction of the tetracyclic skeleton by an aldol reaction followed by formation of the pyranone. The unknown configuration at C14 was assigned as R.
Highly regioselective hydroformylation of 1,5-hexadiene to linear dialdehyde catalyzed by rhodium complexes with tetraphosphorus ligands
Yu, Shichao,Chie, Yu-ming,Zhang, Xiaowei,Dai, Liyan,Zhang, Xumu
experimental part, p. 5575 - 5577 (2011/02/22)
Rhodium-catalyzed hydroformylation of 1,5-hexadiene to corresponding dialdehydes was investigated using tetraphosphorus ligands. These ligands showed a high regioselectivity for linear aldehydes (linear to branch ratio up to 98%) in very good yield (up to 87%). It was found that the introduction of the substituents at the ortho position of the biphenyl moiety has little effect on the regioselectivity and the electron-donating substituents retard the reaction somewhat.
Synthesis and Structural Confirmation of (2S,3R,4R,6E)-2-Acetylamino-3-hydroxy-4-methyl-6-octenoic Acid, a New Amino Acid Produced by Neocosmospora vasinfecta
Kirihata, Mitsunori,Nakao, Yoshinobu,Fukuari, Masashi,Ichimoto, Itsuo
, p. 2228 - 2230 (2007/10/03)
An unusual amino acid, (2S,3R,4R,6E)-2-acetylamino-3-hydroxy-4-methyl-6-octenoic acid (2a) and its stereoisomer (2b), were synthesized by the aldol condensation of (2R,4E)-2-methyl-4-hexenal (5) with tert-butyl isocyanoacetate (6) as the key reaction via trans-oxazoline derivative 7, in which two continuous chiral centers were newly formed.The oxazoline derivative was efficiently hydrolyzed to afford separable N-formyl-β-hydroxy amino acid esters 8a and 8b in a 1:1 ratio.Each diastereomer was transformed into target N-acetyl amino acids 2a and 2b via corresponding amino acids 1a and 1b.
Biosynthesis of Tetronasin: Part 3. Preparation of Deuterium Labelled Tri- and Tetraketides as Putative Biosynthetic Precursors of Tetronasin
Hailes, Helen C.,Handa, Sandeep,Leadlay, Peter F.,Lennon, Ian C.,Ley, Steven V.,Staunton, James
, p. 315 - 318 (2007/10/02)
The preparation of seven deuterium labelled N-acetyl cysteamine thioesters (2a), (2b), (3a), (3b), (4), (5) and (6) as putative biosynthetic precursors of the acyl tetronic acid ionophore tetronasin is described.
A VERSATILE PROTOCOL FOR β-HYDROXY-α-AMINO ACIDS: AN APPLICATION TO (4R)-4--4,N-DIMETHYL-L-THREONINE (MeBmt)
Rao, A. V. Rama,Dhar, T. G. Murali,Bose, D. Subhas,Chakraborty, T. K.,Gurjar, M. K.
, p. 7361 - 7370 (2007/10/02)
cis-Oxazolidinone derivative (30) readily realised from chiral 2,3-epoxy alcohol (27) had been exploited in the synthesis of (4R)-4--4,N-dimethyl-L-threonine (2), an unusual β-hydroxy-α-amino acid present in cyclosporin.The intrinsic featur
A STEREOSPECIFIC SYNTHESIS OF (4R)-4--4,N-DIMETHYL-L-THREONINE (MeBmt)
Rao, A. V. Rama,Dhar, T. G. Murali,Chakraborty, T. K.,Gurjar, M. K.
, p. 2069 - 2072 (2007/10/02)
The utility of readily obtainable cis-oxazolidinone derivative (14) has been explored for the efficient and stereospecific synthesis of (4R)-4--4,N-dimethyl-L-threonine, an unusual syn-β-hydroxy-α-amino acid of cyclosporine.
Preparative-Scale, Facile Synthesis of (2R,4E)-2-Methyl-4-hexenal: A Key Intermediate of (2S,3R,4R,6E)-3-Hydroxy-4-methyl-2-methylamino-6-octenoic Acid (MeBmt)
Deyo, Donald T.,Aebi, Johannes D.,Rich, Daniel H.
, p. 608 - 610 (2007/10/02)
Facile separation and mild acidic hydrolysis of the diastereomeric amides derived from 2-methyl-4-hexenoic acid and L-2-phenylglycinol are used in a rapid, preparative-scale synthesis of (2R,4E)-2-methyl-4-hexenal, a key intermediate of MeBmt.
Asymmetric Glycine Enolate Aldol Reactions: Synthesis of Cyclosporine's Unusual Amino Acid, MeBmt
Evans, David A.,Weber, Ann E.
, p. 6757 - 6761 (2007/10/02)
The chiral glycine synthon, 3c, as its derived stannous enolate, has been demonstrated to undergo a highly syn diastereoselective aldol addition reaction with representative aldehydes to give the adducts 5 (R = C6H5, Me, Me2CH) in yields ranging from 71 to 92percent.The utility of these intermediates has been demonstrated via the subsequent three-step transformation of these adducts to the enantiomerically pure N-methyl β-hydroxy amino acids 1.This reaction methodology has been applied to the asymmetric synthesis of (4R)-4-((E)-2-butenyl)-4,N-dimethyl-L-threonine (1a), an important constituent in the immunosuppressant peptide cyclosporine.Several additional structural analogues of 1a were also prepared in conjunction with this study.
