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Book Review Derivative Spectrophotometry. Low and Higher Order. By G. Talsky

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BOOKS
anodic, cathodic. and indirect electroorganic reactions (92, 56. and 26 pp. respectively), and finally a chapter on various interesting special areas of electrosynthesis (33 pp.).
The introductory chapter presents the
fundamental principles needed for an understanding of electroorganic reactions.
The basic components required to achieve
a successful electrochemical reduction or
oxidation are described (the electrodes,
the electrolytic cell. the conducting electrolyte. and the potentiostat). and the author explains concepts such as direct and
indirect electrochemical reactions. electron transfer, electrode potential. equilibrium potential, and overvoltage.
The anodic reactions discussed in
Chapter 2 include oxidation of hydrocarbons, alcohols, phenols, carboxylic acids.
amines. amides, ethers, esters. N-heterocycles. and organosulfur compounds.
Thus, for example, the author describes
the oxidation of alkanes in the presence of
acetonitrile (acetamidation). the anodic
coupling of arenes, the Kolbe synthesis for
preparing w.w’-disubstituted alkanes. and
the synthesis of poly(2.6-dimethyl-I ,4phenyleneoxide) from 2,6-dimethylphenol. The anodic substitution reactions described include cyanidation, acetoxylation. halogenation. hydroxylation, and
alkoxylation.
The cathodic reactions discussed in
Chapter 3 are electrochemical hydrogenations and reductions of carbonyl. organohalogen, organonitro, and organosulfur
compounds and of N-heterocycles. and
also electrocarboxylation. Thus, for example. cyclopropanes are synthesized
from alkenes in the presence of methylene
bromide at a graphite cathode. which is
combined with a zinc sacrificial anode in
an unpartitioned cell. The reduction and
hydrolysis of purine gives 4-aminomethyl5-amino-2-imidazoline, and the electrocarboxylation of ethene gives succinic
acid. Carbon dioxide is converted to
methanol in a photoelectrochemical reduction using leuco-indigo. and the indigo
thus generated is then reduced back to
leuco-indigo. The latter process forms the
basis of a recently developed solar cell.
In cases where the electron exchange in
an electrochemical oxidation takes place
via a mediator the reaction is said to be
indirect. Chapter 4 deals with indirect
electroorganic reactions, under the headings of oxidative and reductive indirect reactions. Species that can be used as oxidative mediators are the transition metal
ions C e S + and R u 4 + . the halogen cations
I + and Br’, and tris(p-bromopheny1)amine. Metal ions in low oxidation states.
such as Fe2+. Cr”. and Sn” , are effec-
tive as reductive mediators. Anthracene is
used a s an organic reductive mediator.
The final chapter collects together a
number of special areas of electroorganic
synthesis. such as electropolymerization
and the synthesis of natural products.
This book covers all the important
modern developments in electroorganic
synthesis, and by providing a wealth of
literature references enables the reader to
study this interesting field in greater
depth. The inclusion of laboratory recipes
for the electrochemical synthesis of many
different compounds is especially useful.
Moreover, all the information in the book
is very clearly presented. There are few
errors, and those that have occurred d o
not detract from the very high quality of
the book. For example, it was undesirable
to use the same symbol Q for quantity of
charge (p. 14) and for the quotient of the
activities in the Nernst equation (p. 8).
For consistency the formula chosen for
naphthalene on page 95. with five double
bonds (ten rc-electrons). should also have
been used on page 21.
Kurhiii: Sc>!fiW
Lehrstuhl fur Organische Chemie I/2
der Universitiit Bayreuth (Germany)
Derivative Spectrophotometry. Low
and Higher Order. By G. Tulsky. VCH
Verlagsgesellschaft, Weinheim, 1 994.
228 pp., hardcover DM 248.00.ISBN 3-527-28294-7
I approached this book with high expectations, hoping to learn about important applications of derivative methods to
spectroscopic interpretation. However,
my first impressions were that the publishers had not made a very good job of language-polishing, and also that the text
ought have been checked by a proof-reader with a mathematical background. For
me there were many small points that rankled. The impression is given that the infrared region ends at 2.5 pm. thus:
“Higher energies are necessary though.
for electron excitation.” Sometimes things
are expressed in an awkward way, as in
*‘...the curve is computet”, or “...derivative orders contribute only littel ...” In
stating the Lambert-Beer law the mention of Bouguer as the earlier discoverer is
wrongly spelt, and Volkmann is wrongly
cited as the author of a book on “infrared
spectrophotometry”. These printing errors are mildly amusing. but the mistakes
in the mathematical formulas are pure
carelessness, and several times I had to
overcome a strong temptation to abandon
the book. Sometimes plus signs, sub- and
superscripts are missing. while in other
cases a symbol that shoutd be a subscript
is printed at normal height. Occasionally
the wrong result is given for an elementary
operation such as differentiation or calculation of a logarithm-. sorry. such mistakes just cannot be tolerated. Proportional is not the same as equals!
The chapter on derivatives, for example
those of the Gaussian function, is unnecessarily awkward and labored. I cannot
understand why the author has not kept
to a consistent nomenclature (there was
already a hint of this in the discussion of
the various symbols for differentiation).
It seems a little strange that extinction coefficients and band distances are given in
millimeters. And since when is the
Lorentzian band-shape an exponential
function? The Savitzky - Golay smoothing equation (Eq. 3-22) contains printing
errors. Certain general recursion formulas
are cited without mentioning the restrictions stated in the original publications.
I was often reminded of old times when
the author referred to cutting out peaks
and weighing to determine their areas,
and again in the descriptions of instrumentation. Even graphical methods of estimating tangents are included. The Iiterature references too are a little antiquated.
What is the purpose of the short digression on the binary system‘?-It is hardly
necessary to point out that modern computers still use it. I certainly did not think
that analog and hybrid methods still have
an important role in differentiation routines. The literature on digital methods of
smoothing and differentiation is well covered. However, references to some recent
monographs on this subject area should
certainly have been included (e.g., P.
Gans, Dritu Fitting in the Cheniical
Sciences, Wiley, Chichester, 1992). One
would also expect to find a mention of
recent publications on the suppression or
elimination of “spikes”.
The treatment of practical aspects begins with Chapter 4. However, the choice
of examples to illustrate the advantages of
derivative spectroscopy seems to me unconvincing. With regard to the fundamental question of what is the optimal order
of differentiation, the author’s answer is
that every shoulder and turning point in
the original spectrum must appear in the
derivative as an extreme value. It would
also have been useful to compare the
derivative method with alternative procedures that have grown in importance in
the last few years, for example resolution
enhancement using techniques such as the
maximum entropy method or self-deconvolution; these avoid the interference by
satellites that can arise in derivative spec-
BOOKS
ti-oscopy. Regrettably. the liter,'i t ure coverage extends only to 1990. On the other
hand. the survey o f the applications of
derivative spectroscopy. which are summarized in the form of 57 tables. is impressive. Looking through these and noting
the order of differentiation. one finds
that. uith very few exceptions, the derivative spectra are of lower orders with
fourth order ;IS the maximum. Even after
reading this (very expensive) book, it
seeins to me that the use of higher orders
has little to recoininend it.
H . M i c h w l HcJisc
Institut fur Spektrocheinie
und Angewandte Spektroskopie
Dortinund (Germany)
Enzymes in Synthetic Organic Chemistry. (Tetrahedron O r g a n i c Chernistry Series. Vol. 12.) By C.-H. Wong
and G. M . Wliitc~sides. Elsevier,
Oxford. 1994. 370 pp., hardcover
E 55.00/paperback f 25.00.PISBN 008-0?5942-hi0-08-03594 1-8
During the last ten years there has been
a great increase in the use of enzymes in
organic synthesis: ;z survey of the wideranging areas of application of such methods will therefore be ~ e l c o n i e dby everyone interested in using these powerful
catxlysts to wlve problems of synthesis.
This book on the subject contains six
chapters: an introductory one explaining
the basic general principles of enzymatic
catalysis and ;I further five treating important types o r reactions. The first chapter
deals with the physicochemical principles
whereby cnrymatic catalysis increases reaction rates. with the kinetics of such reactions. and \\it11 the effects of the solvent,
temperature. and pH on the specificity of
the enzyme. Further aspects treated here
are the important problem of cofactor regeneration. ;tiid the behavior of enzymes
in organic solvents. The second chapter
describes the use of hydrolyzing enzymes
for the formation or breaking of carbonnitrogen and carbon -oxygen bonds in
amides. peptides. esters, nitriles. and
epoxides; the enzymes used are aniidases.
proteases. esterases, lipases, phosphatases. nitrilases, and epoxide-hydrolases.
The effectiveness of these enzymes, especially for peptide synthcsis and for preparing enantioinerically pure carboxylic acid
derivatives and hydroxy compounds. is illustrated by describing results from about
400 published studies. Chapter 3 is devoted to the use of enzymes in redox reactions. As such reactions usually depend on
nicotinamide cofactors, the question of
cofactor regeneration is discussed in detail. The basic principles of stereoselectivity in redox reactions mediated by
NAD(P) are also explained. Many of the
examples of reductions and oxidations described here involve horse-liver alcohol
dehydrogenase, but the discussion also extends to applications of other alcohol dehydrogenases and of numerous keto-acid
dehydrogenases. a s well as metal-mediated enolate reductases, galactose oxidase,
lipooxygenase, arene dioxygenase, and
various monooxygenases. Chapter 4 is
concerned with carbon-carbon bond forination reactions. a topic of great importance for organic synthesis. In describing
typical applications the authors devote
special attention to enzyme-catalyzed aldo1 reactions, but they also explain how
cyanohydrins, acyloins. and polycyclic
compounds such as isoprenoids and
steroids can be prepared using the appropriate enzymes. The current state of
knowledge on the use of aldolases for
stereoselective syntheses of monosaccharides. neuraminic acid, and related polyhydroxy compounds with many chiral
centers is well described with numerous
examples.
The growth in understanding of the role
of carbohydrates in the functions of the
bacterial cell wall and of their importance
for cell adhesion. cell differentiation, and
cell development has led t o a great upsurge of interest in the syithcsis of oligoand polysaccharides. For solving the various regio- and stereocheinical problems of
such syntheses, enzymatic methods are
becoining ever more important. The influence of these developments is eLident in
Chapter 5 , which is concerned with the
formation of glycosidic bonds by enzymatic catalysis. Reactions for converting
monosaccharides into the reactive nucleoside phosphates needed for glycoside
formation. and the use ol' glycosyl transferases, are described in detail. Here we
see that. in this area especially. the use of
these enzymes on a preparative scale is
still severely handicapped by the difficulty
of obtaining them. Chapter 6 deals with
enzyme-catalyzed addition and elirnination reactions, and the use of enzymes to
catalyze the transfer of phosphate.
methyl, sulfate. and amino groups. In
view of the central importance of phosphoric acid esters in biochemical conversion reactions. much space is devoted to
the regeneration of ATP and the synthesis
of phosphorylated carbohydrates.
The book does not claim to provide a
general introduction to the principles of
enzymology or of biochemistry. However,
by treating the applications in five chapters devoted to important types of reactions it should enable every synthetic organic chemist to gain a quick overview of
the current state of the art in enzymatic
catalysis as an aid to organic synthesis. By
using this book. with the approximately
1500 literature referencej provided. the interested reader will be able to discover
quickly whether there is il good prospect
of solving a particular sqnthetic problem
by such methods. I t can therefore bc recommended to everyone seeking to exploit
the great potential of enqmatic catalysis
in his or her work.
H m s Schick
Abteilung Organische Synthese
Institut fur Angewandte Chemic
Berlin (Germany)
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