Resolution of Optically Active Tris(1,10-phenanthroline)vanadium(II) Complex

Optically Active Coordination Compounds. Part 50.' 4-Fold Symmetry Axes in Optically Active Complex Ions from Natural Nicotine

Are lignins optically active?

The accepted derivation of lignins from non(enzymatically)-controlled radical coupling reactions has been recently challenged, and it is relevant to ascertain unequivocally whether lignins are or are not (as normally assumed) optically active. Two approaches were used. First, DFRC (derivatization followed by reductive cleavage) dimers derived from beta-5- and beta-beta-units in pine lignins, wh...

Preparation of the optically active isomers of S-benzylhomocysteine by enzymatic resolution.

S-Benzylhomocysteine, containing isotopic atoms, has proved to be a key intermediate in the synthesis of labeled methionine and related compounds (1). The need of the optically active isomers of these tagged compounds for various metabolic investigations has prompted us to work out a method for the resolution of S-benzylhomocysteine which would be particularly suitable for small quantities of S...

Optically active diaryl tetrahydroisoquinoline derivatives.

In (1R,3S)-6,7-dimethoxy-3-(methoxydiphenylmethyl)-1-phenyl-1,2,3,4-tetrahydroisoquinoline, C(31)H(31)NO(3), (I), and (1R,3S)-2-benzyl-3-[diphenyl(trimethylsiloxy)methyl]-6,7-dimethoxy-1-phenyl-1,2,3,4-tetrahydroisoquinoline, C(40)H(43)NO(3)Si, (II), the absolute configurations have been confirmed to be R and S at the isoquinoline 1- and 3-positions, respectively, by NMR spectroscopy experiment...

Preparation of optically active allothreonine via optical resolution by replacing crystallization.

An attempt was made to use a simple procedure to obtain D- and L-allothreonine (D- and L-aThr), which are non-proteinogenic alpha-amino acids and are useful as chiral reagents in asymmetric syntheses. DL-aThr that exists as a conglomerate was optically resolved by replacing crystallization with L-alanine (L-Ala) as an optically active co-solute. D-aThr was preferentially crystallized from an aq...