Optical Rotation

Because each member of a pair of enantiomeric molecules differs from the other only in the spatial arrangement of the ligands attached to the chiral center, their physical properties, that is, melting point, boiling point, refractive index, solubility, etc., are identical. The major difference between the isomers of an enantiomeric pair was first observed by Biot in 1815 when he noted that one form of tartaric acid rotated plane-polarized light, whereas another form did not (1). Light is a form...

Atropine Stereochemistry

R1 H. R2 -CH20 COCH2CH2CONH(BSA)1 n *Chiral center FIGURE 4 Structures of drugs and immunogens. tiation as one goes further from the link to protein. This antiserum had good selectivity vs. the isomeric methadols, but exhibited 12 cross-reaction with the N-desmethyl metabolite norLAMM. When norLAMM levels were twice those of LAMM, a 25 positive error was introduced. Such ratios can occur as early as 11 hr after LAMM administration (unpublished results) and may...

Resolution Of Racemates

Pasteur devised three methods to resolve paratartaric acid the first was manual, the second was chemical, and the third could be considered biological or physiological. Because paratartaric acid (also called racemic acid) was the first inactive compound to be resolved into optical isomers (enan-tiomers), an equimolar mixture of two enantiomers is now called a racemate. As indicated in the first lecture, Pasteur, using a hand lens and pair of tweezers, laboriously separated a quantity of the...

In

Trans Trans Trans Trans Cis Cis Cis Cis ' The antiserum was generated from a conjugate of an analog of compound Fig. 5 9a , Source-. Wing and Hammock 41 . cyclopropane ring compare Fig. 5 9c vs. 9d or 9c vs. 9e or 9f . Although the authors attribute this to the closer proximity of the 4' position to the conjugation link 41 , the 4' position is well removed from the link. An alternative explanation would be the flexibility of rotation around the 4' O C bond compared to the rigidity of the...