Question

The structure of the antiviral drug oseltamivir (sold under the trade name Tamiflu) is given below. Answer the questions about this structure. Which orbitals are used for bonding by: Carbon A s p sp + p sp2 + p sp3 Carbon B s p sp + p sp2 + p sp3 Determine the configuration of the chirality centers, carbon atoms C and D. Carbon C R S Carbon D R S Which type of carbon is at the positions E and F? Carbon E primary secondary tertiary quaternary Carbon F primary secondary tertiary quaternary Identify the functional groups G, H, I, and J.

Answer 1

B 20 HON HON outo Pooh (a) oshital used for bencling - Carbon A Carbon B C Sp² Sp+p. 0100 •• (b) Configuration - - Carbon C (E S Carbon Diolus 99) R ( - "(©) type of cafebon position at Eand E-> Carbon E e Carbon F C - primary Hoots Secondary

(d) Fuctional groups G, H, I and Y -> 20 Ono Amide Amine Alkene ester

Answer 2

Concepts and reason

This question is based on the concepts of hybridization, absolute configuration of chirality centers, types of atoms and identification of functional groups.

Hybridization is the process in which two or more orbitals of different energy mix with each other in order to generate same number orbitals of equal energy. Chiral center is the atom which attached to completely different groups or atoms.

Fundamentals

Chemical bonding is essential in order to understand the hybridization and geometry around an atom. count all the sigma bonds and lone pairs in order to determine the hybridization and observing the bonding arrangement cane be useful in order to identify the type of atoms, chirality centers and functional groups. Assigning the R, S configuration involves some rules:

1.Assign the priority order to the groups or atoms.

2.The least prior group should be present at dash bond positions. Count the priority number

in increasing order from 1 to 3. If the order turns out to be clockwise then its R

configuration and if it is anticlockwise then the configuration is S.

3.In case the least prior group is not present at dash bond positions. Clockwise order is

assigned as S and anticlockwise is assigned as R.

Part a

The structure of the compound is given below:

Carbon A is attached to four sigma bonds and zero lone pair of electrons so, hybridization is ${\rm{s}}{{\rm{p}}^3}$ whereas, carbon B is attached to three sigma bonds and zero lone pair hybridization will be ${\rm{s}}{{\rm{p}}^2}$ .

Part b

The absolute configuration of C and D within the compound is given below:

‎

Part c

The representation of type of carbon is given below:

Part d

The functional group representation of the compound is given below:

Ans: Part a

Orbitals used for bonding by carbon A and carbon B are given below:

‎

Part b

The absolute configuration of the chirality centers in the compound is given below:

Part c

The representation of type of carbon is given below:

Part d

The names of the functional groups G, H, I and J are amide, amine, alkene and ester respectively.

Answer 3

1. carbon A is attached to 4 substituents , hybridization is sp³

Carbon B is attached to three substituents, there is one pi bond and 3 sigma bonds, hybridization is sp2 + p

2.

Carbon C is S configuration

Carbon D is R configuration

3.

Carbon E is attached to 2 carbon atoms so it is secondary

Carbon F is primary since it is attached to another atom of carbon

4. Functional groups are:

G = amide

H = amine

I = alkene

J = ester