Pharmaceutical Organic Chemistry-III

Cis-trans isomers are:

• Diastereomers.

• Enantiomers

• Geometric isomers

• Constitutional isomers

Which statement is not true for a meso compound?

• The specific rotation is 0º.

• There are one or more planes of symmetry.

• More than one stereogenic center must be present.

• The stereo chemical labels, (R) and (S), must be identical for each stereogenic centre

Which one of the following can exist in optically active forms?

• cis-1,3-Dichlorocyclohexane

• trans-1,3-Dichlorocyclohexane

• cis-1,4-Dichlorocyclohexane

• trans-1,4-Dichlorocyclohexane

In the absence of specific data, it can only be said that (R)–2–bromopentane is:

• Dextrorotatory (+).

• Levorotatory (–).

• Optically inactive.

• Chiral.

Enantiomers are:

• Molecules that have a mirror image.

• Molecules that have at least one stereogenic center.

• Non-superposable molecules.

• Non-superposable molecules that are mirror images of each other.