59865-23-5Relevant academic research and scientific papers
N-Methylative aziridine ring opening and asymmetric synthesis of MeBmt
Kim, Yongeun,Yoon, Doo-Ha,Ha, Hyun-Joon,Kang, Kyung Yeon,Lee, Won Koo
, p. 5918 - 5920 (2011/11/29)
Asymmetric synthesis of MeBmt, an unusual amino acid constituent of cyclosporine A, was achieved from aziridine-(2R)-carboxaldehyde through the highly stereoselective addition of (E)-crotylboronate and the subsequent N-methylative aziridine ring opening as key steps.
A short synthesis of the unusual amino acid of cyclosporine (4R)-4-[(E)-2-butenyl]-4,N-dimethyl-L-threonine (MeBmt)
Savignac,Durand,Genet
, p. 717 - 722 (2007/10/02)
MeBmt 1 was prepared in four steps from the optically pure (2Z, 4R) 4-methyloct-6-yn-2-en-1-ol 8, Z allylic alcohol containing an alkynyl group at the γ position. The two stereogenic centers C-2 and C-3 in the product were controlled using Sharpless' epoxidation and subsequent ring opening at C-2 of the epoxy acid 10 with methylamine.
N-(9-Phenylfluoren-9-yl)-α-amino Ketones and N-(9-Phenylfluoren-9-yl)-α-amino Aldehydes as Chiral Educts for the Synthesis of Optically Pure 4-Alkyl-3-hydroxy-2-amino Acids. Synthesis of the C-9 Amino Acid MeBmt Present in Cyclosporin
Lubell, William D.,Jamison, Timothy F.,Rapoport, Henry
, p. 3511 - 3522 (2007/10/02)
Serine derived N-(9-phenylfluoren-9-yl)-α-amino ketones were prepared by acylation of primary organometallic reagents with amino acid isoxazolidides.When the amino and hydroxyl functions of serine were constrained in oxazolidine and oxazolidinone rings, alkylation of these ketones as their lithium enolates proceeded regiospecifically with good to excellent diasteroselectivity.Reduction of the oxazolidine and oxazolidinone ketones diastereoselectively led to N-protected 4-alkyl-branched 2-amino 1,3-diols that were subsequently oxidized in two steps, via the N-(9-phenylfluoren-9-yl)-α-amino aldehyde, to produce 4-alkyl-β-hydroxy-α-amino acids.In this way L-(+)-MeBmt (1), the C-9 amino acid of cyclosporin, and its D-(-) enantiomer were prepared in 12 steps from D- and L-serine, respectively, with 22percent overall yield and >99percent enantiomeric purity.N-(9-Phenylfluoren-9-yl)-MeBmt triple-bond and 6Z double-bond analogues 37 and 39 were also prepared.This synthetic route requires only a single chiral source (serine) and provides for configurational choice at all four diastereomeric centres.
Radical Cyclization in Stereospecific Introduction of Chirality at "Off Template Site" of 1,2-O-Isopropylidene-α-D-xylo-hexofuranose
Rao, A. V. Rama,Yadav, J. S.,Rao, C. Srinivas,Chandrasekhar, S.
, p. 1211 - 1213 (2007/10/02)
Bromoacetals derived from 5,6-dideoxy-1,2-O-isopropylidene-α-D-xylo-hex-5-ynofuranose (9) undergo facile free radical cyclization leading to the formation of olefinic acetals which are chemically manipulated to introduce either of the chiralities at C-5 of α-D-hexofuranose.
HIGHLY STEREOSELECTIVE APPROACH FOR β-HYDROXY-α-AMINO ACIDS FROM D-GLUCOSE : THE SYNTHESIS OF MeBmt
Rao, A.V. Rama,Yadav, J.S.,Chandrasekhar, S.,Rao, C. Srinivas
, p. 6769 - 6772 (2007/10/02)
A highly stereoselective protocol for the synthesis of β-hydroxy-α-amino acids from glucofuranose has been developed which has culminated in stereospecific synthesis of MeBmt - an unusual aminoacid component of immunosuppressive peptide cyclosporin.
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.
