In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Optical rotatory dispersion and absolute configuration. Part 20. Chiroptical properties of α-substituted succinic acids. Conformation and absolute configuration, published in 1977, which mentions a compound: 20859-23-8, mainly applied to CD conformation succinate, Synthetic Route of C4H5BrO4.
The effect of conformational preference on the chiroptical properties of α-substituted succinic acids and esters was studied using variable temperature CD in solvents of different polarity. When R1 in the ester RO2CCH2CHR1CO2R (I) is alkyl or halogen, the preferred conformation is II (X = H, Y = R1, Z = CH2CO2R) with the CH2CO2R group eclipsed by the CO bond, whereas when R1 in I is OH, OMe, or NH2, the major conformer is II (X = CH2CO2R, Y = H, Z = R1), in which the heteroatom is eclipsed by the CO bond. In both cases, conformation II (X = R1, Y = CH2CO2R, Z = H) is least favored, mainly on steric grounds. The results when R1 = Cl or Br in I do not support previously proposed conclusions (Listowsky, I. et al., 1970) and an alternative explaination is given. In the resultant octant projection, the sign of the Cotton effect for I will be determined by the position of the groups X and Y in the back octants, and since one of these is always H in the 2 favored conformations, the sign is actually determined by the position of the other group. The octant projection predicts successfully the sign of the ellipticity of the n→π* transition for any α-substituted succinic acid or ester with the appropriate substituent R1, and applied also to simple alkanoic acids and esters with the same substituents.
This literature about this compound(20859-23-8)Synthetic Route of C4H5BrO4has given us a lot of inspiration, and I hope that the research on this compound((S)-2-Bromosuccinic acid) can be further advanced. Maybe we can get more compounds in a similar way.
Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”