Organic Chemistry
Improve your experience by picking them
The specific rotation of the S enantiomer of a proposed cancer treatment drug is −26.9°. A researcher attempted to synthesize an enantiopure form of the said drug but synthesized it with a specific rotation of −22.7°. Determine the S to R ratio of the drug synthesized by the researcher.
Thalidomide is a drug used to treat cancer, several skin disorders, and particular complications caused by human immunodeficiency virus (HIV). The (–)-isomer is the biologically active form of thalidomide. A sample of a mixture of thalidomide has a specific rotation of [α]D = –45.1°. Using the specific rotation of the pure enantiomer below, determine the ratio of (+)- to (–)-thalidomide in the sample.
Limonene is a volatile liquid found in citrus fruits. The (R)-enantiomer is used as a flavoring agent in foods and fragrances in the cosmetic industry. Pure (R)-Limonene has a specific rotation ([α]D) of +115.0°. Predict the specific rotation of a mixture that contains 82% R and 18% S.
A commercial drug has an enantiomeric excess of 86% of R isomer. Determine the percentage of the S isomer.
A solution of pure (R)-2-bromobutane has a specific rotation of -23.1°. If a mixture of stereoisomers of 2-bromobutane shows a specific rotation of −14°, determine the percentage of (R)- and (S)-2-bromobutane in it.
A sample enriched with the R enantiomer has a %ee of 76%. What percentage of the sample is racemic? What is the S to R ratio of the enantiomers in the sample?
A substance has a specific rotation of -40.0. In a polarimeter tube that is 5 cm long, a solution of the compound (0.81 g/100mL) causes an observation of the rotation of -7.52. How much of each enantiomer is in the solution?
An unknown drug has a specific rotation of +82. The commercial synthesis of this drug results in a mixture with an enantiomeric excess of 94%.
a. Determine the absolute configuration (R or S) of this drug.
b. What is the percentage of each of its enantiomers in the commercial product?