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Topic: Fischer projection

Related Topics

Hayworth projection

Stereochemistry

Glucose

Penultimate

Mutarotation

Haworth projection

	Hermann Emil Fischer Summary
		Fischer's first step in unraveling the mysteries of the sugar group was the discovery in 1875 of phenyl hydrazine, a compound which could be used as a general reagent for separating and isolating sugars.
		Fischer was elected to membership in the Academy of Sciences, and, in 1902, he received the Nobel Prize "for his synthesis in the groups of sugars and purine," as quoted by Eduard Farber in Nobel Prize Winners in Chemistry.
		Fischer was born in Euskirchen, near Cologne, the son of a businessman.
	www.bookrags.com /Hermann_Emil_Fischer (4302 words)

	Projection - Wikipedia, the free encyclopedia
		Power projection, the capacity of a state to implement policy by means of force, or the threat thereof, in an area distant from its own territory
		Enamel projections, extensions of dental enamel beyond the normally smooth cervical margin and onto the root of the tooth
		Projection (Cylon ability), the ability to perceive your environment in any form you choose, displayed by the humanoid Cylons in the television series Battlestar Galactica.
	en.wikipedia.org /wiki/Projection (197 words)

	Carbohydrates
		Fischer's initial assignment of the D-configuration had a 50:50 chance of being right, but all his subsequent conclusions concerning the relative configurations of various aldoses were soundly based.
		Remember, a Fischer projection formula may be rotated by 180º in the plane of projection without changing its configuration.
		By convention for the D-family, the five-membered furanose ring is drawn in an edgewise projection with the ring oxygen positioned away from the viewer.
	www.cem.msu.edu /~reusch/VirtualText/carbhyd.htm (4755 words)

	Stereoisomers
		In a Fischer projection drawing, the four bonds to a chiral carbon make a cross with the carbon atom at the intersection of the horizontal and vertical lines.
		Fischer projection formulas are particularly useful for comparing configurational isomers within a family of related chiral compounds, such as the carbohydrates.
		The Fischer projection formula of meso-tartaric acid has a plane of symmetry bisecting the C2–C3 bond, as shown on the left in the diagram below, so this structure is clearly achiral.
	www.cem.msu.edu /~reusch/VirtTxtJml/sterism3.htm (4189 words)

	Assigning Absolute Configurations for Fischer Projections (Site not responding. Last check: 2007-11-03)
		In the lecture notes, you saw that Fischer Projections were a type of short hand for representing molecules with stereogenic centers developed by biochemists.
		It was also shown in lecture that because of this convention, if the Fischer projection was rotated 90° it actually represented another stereoisomer.
		Fischer projections can be rotated 180° and represent the same compound, but they cannot be rotated 90° and be a representation of the same compound.
	www.ipfw.edu /chem/261/Fischer1.htm (237 words)

	Fischer projection - Wikipedia, the free encyclopedia
		In chemistry (particularly organic chemistry and biochemistry), a Fischer projection is a two-dimensional representation of a three-dimensional organic molecule by projection.
		Therefore, a Fischer projection cannot be rotated by (2n+1)×90° in the plane of the page or the screen, as the orientation of bonds relative to one another can change, converting a molecule to its enantiomer.
		Fischer projections are most commonly used in biochemistry to represent monosaccharides, but can also be used for amino acids or for other organic molecules.
	en.wikipedia.org /wiki/Fischer_projection (249 words)

	OCOL
		The conversion of a perspective drawing to a Fischer projection requires rotating the molecule so that the "top" and "bottom" groups are oriented back, away from you.
		A Fischer projection can be rotated and manipulated, and most usefully, can be utilized to assign absolute configuration (R or S) and to compare sets of compounds in order to determine their stereochemical relationship (enantiomers, diastereomers, identical, or meso).
		In order to use a Fischer projection to determine R or S stereochemistry, you need to realize that the "bow-tie" orientation of a Fischer can be gently tilted backward to yield a structure where the top atom is oriented backward, and the remaining groups are coming forward.
	www.chem.uic.edu /web1/OCOL-II/WIN/STEREO/103/FISCHER.HTM (608 words)

	Chem 121
		Write all the fischer projections of all the possible stereoisomers of the following compound and identify the pairs of eneatiomers.
		The pair of stereoisomers that are enantiomers are: 1 and 2, 3 and 4, 5 and 6, and 7 and 8.
		The stereoisomer depicted in the fischer projection of 2,4-pentanediol is achiral even though it contains two chiral carbons because the chiral carbons are equivalent and the stereoisomer contains a plane of symmetry.
	faculty.uccb.ns.ca /chowley/chem110/2002/PROBLEMSET4.htm (239 words)

	Fischer projections
		Fischer Projections are abbreviated structural forms that allow one to convey valuable stereochemical information to a chemist without them having to draw a 3D structural representation of a molecule.
		Fischer projections a can be used to describe molecules with more than one stereogenic centre.
		Assignment of the configuration at a stereogenic center, in a Fischer projection, is based on the Cahn-Ingold-Prelog rules.
	www.mhhe.com /physsci/chemistry/carey/student/olc/ch07projections.html (401 words)

	chapter 3 (Site not responding. Last check: 2007-11-03)
		The convention is that the two vertical bonds in the projection are pointing behind the plane of projection (plane of paper sheet), and the two horizontal bonds are pointing towards the viewer.
		One of the remaining atoms is oriented behind the plane of projection (dashed bond), one towards the viewer (boldface bond).
		This projection is difficult to use with acyclic molecules but is most popular for representation of cyclic molecules e.g.
	tigger.uic.edu /~kbruzik/text/chapter3.htm (390 words)

	Chemistry 210 Experiment 7
		One direct approach, known as the Fischer esterification reaction, involves the acid-catalyzed condensation of an alcohol and a carboxylic acid, yielding an ester and water.
		Fischer was the first to synthesize phenylhydrazine, which was an important reagent in his work on elucidating the structures of most of the carbohydrates.
		Fischer committed suicide in 1919 following the death of his wife and the loss of two of his three sons.
	www.miracosta.cc.ca.us /home/dlr/210exp7.htm (1476 words)

	Models Tutorial -- Page 24
		The rules given for manipulating Fischer projections as given in your text are incomplete.
		Projections, as single units, may be rotated 180° only (not 90°), and only in the plane of the paper.
		The following pair of Fischer projections represents a rotation by 180° in the plane of the paper; click on them to see and compare the corresponding Chime models.
	www.bluffton.edu /~bergerd/Models/chiral7.html (256 words)

	Fischer Projections (Site not responding. Last check: 2007-11-03)
		Fischer projections were invented by the German sugar chemist Emil Fischer to simplify displaying the stereochemical relationships among carbohydrate structures.
		A research project in which I participated some years ago demonstrated conclusively that individuals are better able to perceive structures written with dash-and -wedge notation as three-dimensional, and make more accurate assignments of absolute configuration.
		That the Fischer projection formally places the molecule into an all eclipsed conformation is shown in the second example, where we step through the transformation from Fischer to dash-wedge for a molecule having three chiral centers.
	dwb.unl.edu /Teacher/NSF/C10/C10Links/oldblue.umeche.maine.edu/Fischer.html (305 words)

	BIOdotEDU
		He showed that a molecule such as glucose could have the same atoms connected with the same bonds, to the same neighboring atoms, and yet have very different physical, biological and chemical properties depending on how the bonds and atoms were arranged in three-dimensional space.
		Using Fischer's system, the four covalent bonds of a single carbon atom are drawn in the form of a cross, each bond at a 90
		The viewer then has to imagine that the horizontal bonds (the "left' and "right" bonds) are actually sticking out of the surface and towards the viewer, while the two vertical bonds (the "up" and the "down" bonds) are actually directed into the surface away from the viewer.
	www.brooklyn.cuny.edu /bc/ahp/LAD/C4c/C4c_stereo.html (496 words)

	Biochemistry of Carbohydrates
		When drawn in the Fischer projection, the a configuration places the hydroxyl attached to the anomeric carbon to the right, towards the ring.
		The spatial relationships of the atoms of the furanose and pyranose ring structures are more correctly described by the two conformations identified as the chair form and the boat form.
		Constituents of the ring that project above or below the plane of the ring are axial and those that project parallel to the plane are equatorial.
	web.indstate.edu /thcme/mwking/carbohydrates.html (806 words)

	Glucose animations with Jmol (Site not responding. Last check: 2007-11-03)
		The relation between the Fischer projection of D-glucose and the 3-dimensional structure of the beta-D-glucopyranose ring is shown here in the form of a 40 structure animation.
		The starting structure resembles the Fischer projection: the carbon chain is vertical, the aldehyde at the top, and the horizontal bonds pointing towards you (in agreement with the definition of the Fischer projection).
		Therefore Haworth introduced a projection in which the ring is made flat, and the substituents are pointing either up or down.
	cheminf.cmbi.ru.nl /wetche/organic/gluc/glucjmol.html (273 words)

	SparkNotes: Stereochemistry: Fischer Projections
		Because the "up" and "down" aspects of the bonds don't change, a Fischer projection may be rotated by 180 degrees without changing its meaning.
		A Fischer projection may not be rotated by 90 degrees.
		To determine whether the molecule in Fischer projection is a meso compound, draw a horizontal line through the center of the molecule and determine whether the molecule is symmetric about that line.
	www.sparknotes.com /chemistry/organic3/stereochemistry/section1.html (232 words)

	Glyceraldehyde and the Fischer Projection: Drawing the Fischer Projection
		The shadow of a molecular model of glyceraldehyde is used to draw its Fischer projection.
		A Fischer projection is often used to show the configuration of carbohydrates and amino acids.
		To draw the Fisher projection of D-glyceraldehyde orient the carbon chain vertically and trace the outline of the atoms using horizontal lines for substituents.
	jchemed.chem.wisc.edu /JCESoft/CCA/CCA5/MAIN/1ORGANIC/ORG09/TRAM09/D/0283703/THUMBS.HTM (93 words)

	[No title]
		A 180º rotation (slide) of the drawing in the plane of the paper generates a projection of the same enantiomer.
		Two different Fischer projections represent the same enantiomer if one projection can be converted to the other by an even number of switches.
		The projection is drawn with the carbon chain vertical, and 180º rotation (slide) gives the same enantiomer.
	web.pdx.edu /~lutzr/Fischer.doc (454 words)

	Carbos (Site not responding. Last check: 2007-11-03)
		In order to be able to draw three dimensional structures and reason about absolute stereochemistry, Emil Fischer assigned (i.e., guessed) the absolute stereochemistry of glyceraldehyde and said the D-isomer was the one shown in the Figure.
		In 1888 Emil Fischer and his students undertook the determination of the total structure of glucose, including the determination of the configuration at each chiral centre.
		Fischer had synthetically prepared a number of carbohydrates, and had synthesized many unnatural L-sugars.
	instruct.uwo.ca /chemistry/223b-98/carbos.htm (4143 words)

	Steve's place - Carbohydrates
		C5) in the Fischer projection, and in the Haworth projection, hence D-glucose.
		This way of drawing monosaccharides is called a Fischer projection: imagine the vertical bonds curling away from you and the horizontal bonds sticking out at you, like the back of a stegosaurus.
		Remember that the Fischer projection curves away from you, with the OH and H groups sticking out like the plates on a stegosaur's back.
	www.steve.gb.com /science/carbohydrates.html (2287 words)

	[No title]
		Fischer Projections Fischer projections are drawn with a cross, with the chiral atom at the center of the cross.
		Fischer projections that differ by a 180° rotation are the same enantiomer, since the vertical lines are still back, and the horizontal lines are still forward.
		To use the Fischer projection, ensure the Fischer projection is drawn correctly.
	crab.rutgers.edu /~alroche/Ch05.doc (2911 words)

	Monosaccharides
		When Emil Fischer took up this problem about 100 years ago, he realized that there was no way to determine if glucose was one of the eight structures above or one of the unshown enantiomers.
		He made the assumption that it was one of the ones above so that he could work on the diastereoisomeric part of the problem, hoping that later work would resolve the question of which enantiomer best represented glucose.
		Fischer noticed that if reactions could be developed which changed the aldehyde group into a primary alcohol and the primary alcohol into an aldehyde (switch ends) one of these structures would give itself, and the other would give back a new
	chemistry2.csudh.edu /rpendarvis/monosacch.html (1764 words)

	[No title]
		in the standard Fischer projection for carbohydrates, the aldehyde group is at the top; for ketoses, the ketone group is as close to the top as possible; for amino acids, the carboxyl group is at the top.
		The b-anomer can be identified in the following manner: In the Fischer projection with the ring O shown to the right of the vertical axis, the anomeric –OH is on the left.
		In the Haworth projection, the anomeric –OH is on the same side of the ring as the terminal –CH OH group [up for D-sugars].
	www.mpcfaculty.net /ron_rinehart/30B/sugrtabl.htm (1064 words)

	Structure in Three Dimensions
		The Br is in front of the plane, the H is behind it, and the methyl (to the left) and ethyl (to the right) groups are taken as being in the plane (at least the carbons of those groups).
		The other representation is known as the Fischer projection.
		The last "equals" sign says that the Fischer projection and the perspective view are representations of the same molecule.
	chemistry2.csudh.edu /rpendarvis/chirality.html (1232 words)

	Glycobiology Resources: Monosaccharides (Site not responding. Last check: 2007-11-03)
		Fischer Projection Formulae are used to identify the configuration at the chiral centers of a sugar.
		The sugar is oriented so that the carbon skeleton is vertically aligned with the aldehyde at the top and the alchohol at the bottom, so that vertical substituents are shown below the plane of the page, while horizontal substituents are shown above.
		The projection of the vertical and horizontal substituents are shown as plain vertical and horizontal lines, giving the Fischer Projection of the chiral center.
	glycores.ncifcrf.gov /mono (590 words)

	Glossary for Web Pages
		The geometric arrangement around carbon-carbon single bonds in which the bonds to substituents on one carbon are parallel to the bonds of substituents on neighboring carbon atoms as viewed in a Newman projection.
		A Fischer projection uses a cross to represent the stereogenic center.
		Haworth projections are drawn so that the ring is flat and is viewed from an oblique angle with the hemiacetal oxygen at the upper right.
	www.personal.psu.edu /faculty/t/h/the1/glossary.htm (2931 words)

	Chapter21
		It is customary to have the aldehyde group (and the keto group) represented on the top (portion) in the Fischer representation of these molecules.
		We have just seen that glucose is an aldohexose therefore it is possible for the aldehyde group of glucose to react reversibly with a OH group in the molecule to form a cyclic hemiacetal.
		Rotate the Fischer representation by 90 degrees in the plane of the paper.
	www.wiu.edu /users/mftkv/CHEM330(00)/Chapter16.htm (1364 words)

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