Instructor's Guide and Solutions Manual to Organic Structures from 2D NMR Spectra, Instructor's Guide and Solutions Manual

L. D. Field, A. M. Magill, H. L. Li

• Publisher: Wiley
• Year: 2015
• Print ISBN: 9781119027256
• eBook ISBN: 9781119027270
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Spectroscopy & Spectrum Analysis

The text Organic Structures from 2D NMR Spectra contains a graded set of structural problems employing 2D-NMR spectroscopy. The Instructors Guide and Solutions Manual to Organic Structures from 2D NMR Spectra is a set of step-by-step worked solutions to every problem in Organic Structures from 2D NMR Spectra. While it is absolutely clear that there are many ways to get to the correct solution of any of the problems, the instructors guide contains at least one complete pathway to every one of the questions. In addition, the instructors guide carefully rationalises every peak in every spectrum in relation to the correct structure. The Instructors Guide and Solutions Manual to Organic Structures from 2D NMR Spectra: Is a complete set of worked solutions to the problems contained in Organic Structures from 2D NMR Spectra. Provides a step-by-step description of the process to derive structures from spectra as well as annotated 2D spectra indicating the origin of every cross peak. Highlights common artefacts and re-enforces the important characteristics of the most common techniques 2D NMR techniques including COSY, NOESY, HMBC, TOCSY, CH-Correlation and multiplicity-edited C-H Correlation. This guide is an essential aid to those teachers, lecturers and instructors who use Organic Structures from 2D NMR as a text to teach students of Chemistry, Pharmacy, Biochemistry and those taking courses in Organic Chemistry.

Problem 1

Question:

The ¹H and ¹³C{¹H} NMR spectra of 1-iodopropane (C₃H₇I) recorded in CDCl₃ solution at 298 K and 400 MHz are given below.

The ¹H NMR spectrum has signals at δ 0.99 (H₃), 1.84 (H₂) and 3.18 (H₁) ppm.

The ¹³C{¹H} NMR spectrum has signals at δ 9.6 (C₁), 15.3 (C₃) and 26.9 (C₂) ppm.

Also given on the following pages are the ¹H–¹H COSY, ¹H–¹³C me-HSQC, ¹H–¹³C HMBC and INADEQUATE spectra. For each 2D spectrum, indicate which correlation gives rise to each cross-peak by placing an appropriate label in the box provided (e.g. H₁ → H₂, H₁ → C₁).

Solution:

1. ¹H–¹H COSY spectra show which pairs of protons are coupled to each other. The COSY spectrum is always symmetrical about a diagonal. In the COSY spectrum, there are two ³J_H–H correlations above the diagonal (H₁ → H₂ and H₂ → H₃). There are no long-range correlations.

2. The ¹H–¹³C me-HSQC spectrum shows direct (one-bond) correlations between proton and carbon nuclei, so there will be cross-peaks between H₁ and C₁, H₂ and C₂ and also between H₃ and C₃. As the spectrum is multiplicity edited, the cross-peaks corresponding to CH₂ groups are shown in red and are of opposite phase to those for CH₃ groups.

3. In HMBC spectra, remember that, for alkyl systems, both two- and three-bond C–H coupling can give rise to strong cross-peaks.

4. H₁ correlates to C₂ and C₃. H₂ correlates to C₁ and C₃. H₃ correlates to C₁ and C₂.

5. The INADEQUATE spectrum shows one-bond ¹³C–¹³C connectivity. There are correlations between C₁ and C₂, and C₂ and C₃.

Problem 2

Question:

The ¹H and ¹³C{¹H} NMR spectra of 2-butanone (C₄H₈O) recorded in CDCl₃ solution at 298 K and 400 MHz are given below.

The ¹H NMR spectrum has signals at δ 1.05 (H₄), 2.14 (H₁) and 2.47 (H₃) ppm.

The ¹³C{¹H} NMR spectrum has signals at δ 7.2 (C₄), 28.8 (C₁), 36.2 (C₃) and 208.8 (C₂) ppm.

Also given on the following pages are the ¹H–¹H COSY, ¹H–¹³C me-HSQC, ¹H–¹³C HMBC and INADEQUATE spectra. For each 2D spectrum, indicate which correlation gives rise to each cross-peak by placing an appropriate label in the box provided (e.g. H₁ → H₂, H₁ → C₁).

Solution:

1. ¹H–¹H COSY spectra show which pairs of protons are coupled to each other. The COSY spectrum is always symmetrical about a diagonal. In the COSY spectrum, there is only one ³J_H–H correlation above the diagonal (H₃ → H₄). There are no long-range correlations.

2. The ¹H–¹³C me-HSQC spectrum shows direct (one-bond) correlations between proton and carbon nuclei, so there will be cross-peaks between H₁ and C₁, H₃ and also between C₃ and H₄ and C₄. As the spectrum is multiplicity edited, the cross-peaks corresponding to CH₂ groups are shown in red and are of opposite phase to those for CH₃ groups.

3. In HMBC spectra, remember that, for alkyl systems, both two- and three-bond coupling can give rise to strong cross-peaks. There are no one-bond C–H correlations.

4. H₁ correlates to C₂ and C₃. H₃ correlates to C₁, C₂ and C₄. H₄ correlates to C₂ and C₃.

5. The INADEQUATE spectrum shows one-bond ¹³C–¹³C connectivity. There are correlations between C₁ and C₂, C₂ and C₃ and C₃ and C₄.

Problem 3

Q...

Table of contents

• Cover
• Half Title page
• Title page
• Copyright page
• Preface
• Problem 1
• Problem 2
• Problem 3
• Problem 4
• Problem 5
• Problem 6
• Problem 7
• Problem 8
• Problem 9
• Problem 10
• Problem 11
• Problem 12
• Problem 13
• Problem 14
• Problem 15
• Problem 16
• Problem 17
• Problem 18
• Problem 19
• Problem 20
• Problem 21
• Problem 22
• Problem 23
• Problem 24
• Problem 25
• Problem 26
• Problem 27
• Problem 28
• Problem 29
• Problem 30
• Problem 31
• Problem 32
• Problem 33
• Problem 34
• Problem 35
• Problem 36
• Problem 37
• Problem 38
• Problem 39
• Problem 40
• Problem 41
• Problem 42
• Problem 43
• Problem 44
• Problem 45
• Problem 46
• Problem 47
• Problem 48
• Problem 49
• Problem 50
• Problem 51
• Problem 52
• Problem 53
• Problem 54
• Problem 55
• Problem 56
• Problem 57
• Problem 58
• Problem 59
• Problem 60
• Problem 61
• Problem 62
• Problem 63
• Problem 64
• Problem 65
• Problem 66