The earliest literature reference for the optical rotation of a pure enantiomer

Question

The earliest literature reference for the optical rotation of a pure enantiomer of a chiral stereoisomer of structures m-t lists a specific rotation of 7.35°. If a more recent specific rotation for the same pure enantiomer is listed as 10.3°, what was the % composition of the major enantiomer of the 7.35° mixture?

please explain the part w/ the 100% and 50% in your answer with the answer choice..

4. The earliest literature reference for the optical rotation of a pure enantiomer of a chiral stereoisomer of structures m-t lists a specific rotation 7.350. more recent reference gives a specific rotation of 10.3 for the same pure enantiomer, assuming this latter rotation is correct, what was the composition of the major enantiomer of the 7.35° mixture? Interestingly, an elevated ratio of the major to minor enantiomer is an indication of a yeast infection in humans. a. (1+7.35/10.3)x100% b. (1-7.35/10.3)x 100% c. (1+7.35/10.3)x50% d. (1-7.35/10.3)x50% e. not a -d.

Explanation / Answer

specific rotation of pure enantiomer = 10.3 degree

specific rotation of mixture = 7.35 degree

So enantiomeric excess of major isomer = 7.35 x 100/10.3 = 71.4 %

remaining = 100 - 71.4 = 28.6% is racemic

Total % of major enentiomer = 71.4 + (28.6/2) = 85.7%

answer : e. not a-d

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.