Question

19) How many of the following statements are true? 

i) Enantiomers are always chiral 

ii) A molecule that has a plane of symmetry can never be chiral. 

iii) An achiral molecule will always have an enantiomer. 

iv) A chiral molecule will always have an enantiomer 

v) Enantiomers are always nonsuperimposable 

a) 0  b) 1  c) 2 d) 3 e) 4 ab) 5

20. Identify the stereochemistry in each of the following compounds as R or S.

Give the correct IUPAC name for the following compounds. For alkenes, when appropriate, indicate whether the alkene is the cis or the trans isomer.

Answer 1

Correct option is "e". Among these options ,option iii is wrong. An achiral molecule will not have an enantiomer 20) Correct option is "a") i = R, II ES i) NH clock wise orientation of priority groups (excluding last priority group), hence configuration is R. (R)-cyclopent-2-en-1-amine الي OH clock wise orientation of priority groups (excluding last priority group), but the least priority group present above the plane hence configuration is S (S)-pyrrolidine-3-carboxylic acid 1)a) To give the E and Z nomenclature to the double bond, if same priority number (molecular weight wise) on the same side then that alkene is Z. (Z)-4-ethyl-3-methylhept-3-ene b) BH 2 To give the E and Z nomenclature to the double bond, if same priority number (molecular weight wise) on the same side then that alkene is Z. (Z)-3-bromo-4-methyloct-3- ene