Fischer projections formulas for

Without consulting chapter figures, draw Fischer projection formulas for glycine, aspartate, leucine, isoleucine, methionine, and threonine. 

Scheme 9. The threo 2,3-diol problem. The erythro/threo notation is based on Fischer projection formulas. For example, if threo 2,3-diol 28, shown here in a staggered zigzag conformation, was depicted in an eclipsed Fischer projection, the adjacent hydroxyls attached to carbons 2 and 3 would reside on opposite sides of the carbon chain. An alternative, perhaps less ambiguous, descriptor is the syn/anti notation.63...

The ring system in these dianhydro hexitols is of interest and worthy of some discussion. The formula of isomannide (LXX) based on the Fischer projection formula for sugars does not convey the real character of the molecule and the author has chosen to write these substances as two fused tetrahydrofuran rings. Scale models show this to be a more exact representation. Thus isomannide is written as LXXI, isosorbide as LXXII, and L-isoidide as LXXIII. 

Draw Fischer projection formulas for all the possible different configuration isomers of the following substances ... 

Draw the Fischer projection formula for a simple monosaccharide. 

Convert the Fischer projection formula for a tetrose to a sawhorse or Newman projection formula, and vice versa. 

Draw the Fischer projection formula for the sympathomimetic oxilofrine (erythro configuration) and then convert this formula into a zigzag projection. As a check determine the absolute configuration at each step. 

The Fischer projection formula for D-glucose (Example 2.3) is also known as the open- or straight-chain structure. This structure occurs only in solution. There are two crystalline forms of D-glucose, known as a and /3, which also have different optical activities when dissolved. X-ray diffraction studies have confirmed chemical evidence that a- and /3-D-glucose are structures containing a ring of five carbon atoms and one oxygen atom ... 

Write the Fischer projection formulas for the sugar derivatives named in Example 2.20. 

PROBLEM 8.4 The Fischer projection formula for (+)-2-bromooctane is shown. Write the Fischer projection of the (-)-2-octanol formed from it by nucleophilic substitution with inversion of configuration. 

Draw a Fischer Projection formula for each of the following compounds. Indicate each of the chiral carbons with asterisks ( ). 

Table 17.1 shows the names and Fischer projection formulas for all D-aldotrioses, tetroses, pentoses, and hexoses. Each name consists of three parts. The letter D specifies the configuration at the stereocenter farthest from the carbonyl group. Prefixes, such as rib-, arabin-, and glue-, specify the configurations of all other stereocenters relative to one another. The suffix -ose shows that the compound is a carbohydrate. 

With the exception of glycine, FI2NCH2COOH, all protein-derived amino acids have at least one stereocenter and therefore are chiral. Figure 18.2 shows Fischer projection formulas for the enantiomers of alanine. The vast majority of carbohydrates in the biological world are of the D series (Section 17.2), whereas the vast majority of a-amino acids in the biological world are of the L-series. 

PROBLEM 5.15 Draw a Fischer projection formula for (S)-lactic acid. 

Let us see how to use Fischer projection formulas for these molecules. Consider the (2R,3R) isomer, the one at the left in Figure 5.12. The solid-dashed wedge drawing has horizontal groups projecting out of the plane of the paper toward us and vertical... 

PROBLEM 5.19 The Fischer projection formula for glucose (blood sugar, Sec. 16.4, p. 466) is... 

PROBLEM 16.1 Using Figure 16.1, write the Fischer projection formula for a. L-arabinose b. i.-mannose... 

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