Effect of Solvent on the Optical Rotation of Azatryptophan Derivatives.

Chirally pure enantiomers of differently protected 7-azatryptophan derivatives (R-3c, S-3c, R-3i, S-3i, R-3m, S-3m, R-3aa, and S-3aa) were synthesized, which showed solvent-dependent optical rotation. The obtained results not only exhibited changes in the values but also showed the variation in sign (- or +) with the different solvents studied. The change in optical rotation value was essentially attributed to the electron-donating property, which can be correlated to the donor number of the solvents.

Regioselective synthesis of phenanthrenes and evaluation of their anti-oxidant based anti-inflammatory potential.

Regioselective synthesis of 9,10-dihydro-2,5-dimethoxyphenanthrene-1,7-diol (1) and 9,10-dihydro-2,7-dimethoxyphenanthrene-1,5-diol (2) was achieved using regioselective methylation, Wittig reaction, intramolecular cyclization and hydrogenation as key steps. The synthesis was successfully completed in total of 15 steps with 3.3% overall yield in case of 1 and in total of 13 steps with 9.