Question

Note there are 110 total points on this exam: 10 points of extra credit is included 1. Provide a brief definition of the following terms including a specific example for each provide examples in addition to a definition. (10 points, 2 points each) a. Diastereomer Diastereomer b. Syn addition (in alkene addition reactions) c. Fischer projection d. Electrophile e. Markovnikov's Rule

Answer 1

the brief definition is given below, also the examples are given in image. Please see image for example.

(a) Diastereomers :

the stereoisomers, which are not mirror image of each other are called Diastereomers. And the phenomenon is called Diastereomerism. Diastereomers have different spatial arrangements of substituent around one or more(but not all) of the equivalent stereocenters.

Example: cis -2- butene and trans-2-butene have same chemical formula but they are not mirror image of each others therefore they can be called Diastereomers. structure given in image

(B) Syn addition : in alkene addition reaction, when the addition of any group takes place at the same side of the double bond of alkenes then, it is called syn addition.

example: given in image

(C) Fisher projection: When any molecule which is in 3D , a convention is used to draw that molecule into 2D also, the stereochemical information of molecule such as , configuration is same, the convention used is called as Fisher projection.

Example: R lactic acid is in 3-D , when it can be drawn in 2-D by using Fischer projection which is shown in image.

(D) electrophile : the species, which is positively charged or neutral , but having vacant orbitals are known to be electrophile. It is also called e- seeking reagent because they attracts toward higher negative charge density.

example : H+ , Br+, H3O+, BF3, AlCl3, etc.

(E) Markovnikov's rule: The addition of HX (X= cl,br, etc.) to an unsymmetrical alkene takes place via Markovnikov's rule, according to this rule, the Hydrogen is attached to that Carbon which has more number of Hydrogen atoms, while the halogen X is attached to the Carbon which has less number of Hydrogen atoms.

example : given in image

Dia stereoisomen example! M. CH₂ G H CHg cl-2-butene trovy-2-buture Both are not mirror image of each other, called H OH © Syn additoncin alkene ad diton reaction). BH₂- H H BM2 a tew steps at Syn addition same side addition of Hond-OH. (C) Fischer projection! CHg е Ня LH - Y HOH Hooc YOH Cool 3-0 formula 9-D R-Lactic acid R- Loctic acid (fitchen formida (@) Markouni kauls Rulle! Mkv addition + Hy + HX MOOR "alken, R