
Concept explainers
17-54 Following is the structure of immunosuppressant FK-506, a molecule shown to disrupt calcineurin-mediated signal transduction in T-lymphocytes.
(a) There are three carbon—carbon double bonds present in this molecule. Which of the three has the potential for cis/trans isomerism? Assign a cis or trans con?guration to each carbon-carbon double bond that has this possibility.
(b) How many stereocenters are present in this molecule? How many stereoisomers are possible for it?
(c) Are there any aromatic components in this molecule?
(d) Consider the two carbon atoms marked with asterisks. Assign an R or S con?guration of each stereocenter.
(e) Because of the presence of a 21-member ring, this molecule is described as a macrocycle. This ring is fashioned by three types of bonds, several carbon-carbon bonds, one ester, one hemiacetal, and one amide. Locate the ester and the hemiacetal.
(f) Draw the structural formula of the long chain compound that would result if the hemiacetal were to be cleaved to an alcohol and a carbonyl group.

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Chapter 17 Solutions
Introduction to General, Organic and Biochemistry
- Q5: Label each chiral carbon in the following molecules as R or S. Make sure the stereocenter to which each of your R/S assignments belong is perfectly clear to the grader. (8pts) R OCH 3 CI H S 2pts for each R/S HO R H !!! I OH CI HN CI R Harrow_forwardCalculate the proton and carbon chemical shifts for this structurearrow_forwardA. B. b. Now consider the two bicyclic molecules A. and B. Note that A. is a dianion and B. is a neutral molecule. One of these molecules is a highly reactive compound first characterized in frozen noble gas matrices, that self-reacts rapidly at temperatures above liquid nitrogen temperature. The other compound was isolated at room temperature in the early 1960s, and is a stable ligand used in organometallic chemistry. Which molecule is the more stable molecule, and why?arrow_forward
- A mixture of C7H12O2, C9H9OCl, biphenyl and acetone was put together in a gas chromatography tube. Please decide from the GC resutls which correspond to the peak for C7,C9 and biphenyl and explain the reasoning based on GC results. Eliminate unnecessary peaks from Gas Chromatography results.arrow_forwardIs the molecule chiral, meso, or achiral? CI .CH3 H₂C CIarrow_forwardPLEASE HELP ! URGENT!arrow_forward
- Identify priority of the substituents: CH3arrow_forwardHow many chiral carbons are in the molecule? OH F CI Brarrow_forwardA mixture of three compounds Phen-A, Acet-B and Rin-C was analyzed using TLC with 1:9 ethanol: hexane as the mobile phase. The TLC plate showed three spots of R, 0.1 and 0.2 and 0.3. Which of the three compounds (Phen-A; Acet-B or Rin-C) would have the highest (Blank 1), middle (Blank 2) and lowest (Blank 3) spot respectively? 0 CH: 0 CH, 0 H.C OH H.CN OH Acet-B Rin-C phen-A A A <arrow_forward
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningOrganic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning



