Chapter 7, Problem 4LGP

Interpretation Introduction

Interpretation:

The retro synthesis analysis for the given compound is to be developed, the reactions are to be written for the synthesis of this compound, the synthetic intermediates show IR absorption that would result from retrosynthetic analyses and its 3-d structure of major product is to be drawn.

Concept Introduction:

▸ Electrophiles are electron deficient species which has positive or partially positive charge. Lewis acids are electrophiles which accept electron pair.

▸ Nucleophiles are electron rich species which has negative or partially negative charge. Lewis bases are nucleophiles which donate electron pair.

▸ Substitution reaction: A reaction in which one of the hydrogens of a hydrocarbon or a functional group is substituted by any other functional group.

▸ Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed.

▸ Addition reaction: A reaction in which unsaturated bonds are converted to saturated molecules by addition of molecules.

▸ Retrosynthesis: A process by which the reaction used to form target product is deduced by determining the immediate reactant used to produce it and then repeating the step again to determine other precursors.

▸ The molecules which are non-superimposable or not identical with their mirror images are known as chiral molecules.

▸ A pair of two mirror images which are non-identical is known as enantiomers which are optically active.

▸ The objects or molecules which are superimposable with their mirror images are achiral objects or molecules and these objects have a centre of symmetry or plane of symmetry.

▸ The achiral compounds in which plane of symmetry is present internally and consists of chiral centres are known as meso compounds but they are optically inactive.

▸ The stereoisomers which are non-superimposable on each other and not mirror images of each other are known as diastereomers.

▸ Chiral molecules are capable of rotating plane polarized light

▸ The molecules which are superimposable or identical with their mirror images are known as achiral molecules, and achiral molecules are not capable of rotating the plane-polarised light.

▸ The reaction in which hydrogen is added to the compound in the presence of catalyst is known as hydrogenation.

▸ The number of moles of hydrogen absorbed will be equal to the number of double bonds.

▸ Infrared spectroscopy is a simple, instrumental technique, which helps to determine the presence of various functional groups.

▸ It depends on the interactions of atoms or molecules with the electromagnetic radiation.

▸ Sodium amide is a strong base and it helps in the formation of acetylide that can be converted into bigger alkyne by adding alkylhalide.

▸ Reduction is a process in which hydrogen atoms are added to a compound. Usual reagent used in reduction process is ${\text{H}}_2/\text{Pt}/\text{pressure}$ or ${\text{H}}_2/\text{Ni}/\text{pressure}$

▸ Chair conformations: It is the most stable conformation, which accurately shows the spatial arrangement of atoms.

▸ Equatorial bonds are parallel to the average plane of the ring, while axial bonds are perpendicular to the average plane of the ring.

▸ The conformation having bonds at the equatorial positions are more stable than those with bonds at the axial position.

▸ On flipping the cyclohexane ring, axial bonds become equatorial bonds and equatorial bonds becomes axial bond.

▸ Bulkier group acquires equatorial positions to form stable conformer due to steric factors.

▸ In double bond or cyclic compounds, if two same functional groups are present on the same side of the double bond or cyclic compound, the given compound can be labeled as cis.

▸ If the two functional groups are present on the different sides of the double bond or cyclic compound, the given compound can be labeled as Trans.

▸ Cis-trans isomerism exists in the compounds in which similar groups are present on the adjacent carbon atoms.