127913-31-9Relevant academic research and scientific papers
Short Synthesis of (+)-Actinobolin: Simple Entry to Complex Small-Molecule Inhibitors of Protein Synthesis
?vejkar, Ji?í,?venda, Jakub,Gysin, Marina,Hobbie, Sven N.,Mikhaylov, Andrey A.,Tharra, Prabhakara R.
supporting information, (2022/03/03)
We report a concise synthesis of the naturally occurring protein synthesis inhibitor (+)-actinobolin (1). The densely functionalized and stereochemically complex molecular structure of 1 was assembled from (?)-quinic acid, L-threonine, and L-alanine as the principal components. Our route is based around a convergent strategy that features conjugate addition of an α-amino radical in the key fragment-coupling step. The dramatically simplified synthesis of (+)-actinobolin proceeding in 9 steps with 18 % overall yield has practical implications for analog preparation, as demonstrated herein.
Direct access to N-H-aziridines from asymmetric catalytic aziridination with borate catalysts derived from vaulted binaphthol and vaulted biphenanthrol ligands
Lu, Zhenjie,Zhang, Yu,Wulff, William D.
, p. 7185 - 7194 (2008/02/05)
The asymmetric catalytic aziridination reaction (AZ reaction) of N-dianisylmethylimines (N-DAM-imines) with ethyl diazoacetate is developed with chiral catalysts prepared from triphenylborate and both the vaulted binaphthol (VANOL) and vaulted biphenanthrol (VAPOL) ligands. Catalysts derived from both ligands were equally effective in terms of asymmetric induction, but the VANOL catalyst was slightly faster. Up to 400 turnovers could be achieved with the VANOL catalyst while still maintaining ≥90% ee in the aziridine product. The ligand could be recovered in 95% yield with no loss in optical purity. Excellent asymmetric inductions were observed with arylimines, and although slightly lower inductions were observed for alkyl-substituted imines, the optical purity of the aziridines from all of the imine substrates could be enhanced to ≥ 99% ee with a single crystallization. Methods were developed for deprotection of the N-DAM-aziridines under acidic conditions without causing an acid-promoted opening of the ring. Excellent yields of the N-H-aziridines could be obtained with both alkyl- and aryl-substituted aziridines. Finally, activation of the N-H-aziridines was achieved with Boc, tosyl, and Fmoc groups. The activated aziridines can be converted to β3-amino esters, and unexpectedly, the N-Boc-protected aziridine-2-carboxylate 16b with a phenyl substituent in the 3-position cis to the ester group was found to undergo ring expansion to a mixture of cis- and trans-oxazolidinones.
Synthesis of L-β-hydroxyaminoacids using serine hydroxymethyltransferase
Saeed, Ashraf,Young, Douglas W.
, p. 2507 - 2514 (2007/10/02)
The enzyme serine hydroxymethyltransferase (EC 2.1.2.1) has been used in the synthetic direction with a variety of aldehyde substrates to form carbon---carbon bonds with the creation of two chiral centres. A variety of β-hydroxyaminoacids has been prepared in reasonable yields but, although L-stereo specificity is observed at the α-centre, stereospecificity is not high at the β-centre when the reaction is conducted on the preparative scale.
Iodocyclization of the (Tolylsulfonyl)- and (Trichloroacetyl)carbamates of Secondary α-Allenic Alcohols. Highly Diastereoselective Synthesis of syn-1,2-Amino Alcohols and trans-5-Alkyl-1-oxo-2-oxazolidine-4-carboxylic Acids
Friesen, Richard W.,Kolaczewska, Aleksandra E.
, p. 4888 - 4895 (2007/10/02)
The iodocyclization of tosyl- and (trichloroacetyl)carbamates 9 and 10, respectively, of secondary α-allenic alcohols is described.The cyclofunctionalization reactions are highly diastereoselective, providing trans-5-alkyl-4-(1-iodoethylene)-2-oxazolidino
RAPID SYNTHESIS OF β-HYDROXY-α-AMINO ACIDS, SUCH AS L-THREONINE, β-HYDROXYPHENYLALANINE, AND β-HYDROXYLEUCINE, VIA AN APPLICATION OF THE SHARPLESS ASYMMETRIC EPOXIDATION
Jung, Michael E.,Jung, Young H.
, p. 6637 - 6640 (2007/10/02)
The optically active epoxy alcohols 6abc, prepared by a Sharpless kinetic resolution-epoxidation process, were converted to the optically pure β-hydroxy-α-amino acids 1abc in four steps and high overall yield.
