Question

please answer in multiple choice format

What is the relationship between these two 23. What is the relationship between these two molecules? molecules? BH BH que a. identical b. enantiomers c. diastereomers d. constitutional isomers 19. Which statement is FALSE about chiral molecules? a. Their chiral Carbons are sp hybridized. b. They have an internal plane of symmetry. c. They are optically active. d. Chiral centers are bonded to four different groups. a. enantiomers b. diastereomers c. identical d. unrelated 20. How many stereoisomers are possible for this molecule? HOF 24. Select the meso compound. CH.CH H- OH OH - H CH.CH XCH 6. Hot a. 4 b.9 6.8 d. 6 21. Which molecule is NOT CHIRAL? 9 HO NH2 HO a. H on c. 25. Select the molecule that results from replacing the pro-8 hydrogen in this molecule: CH 4 H- 22. Indicate the absolute configuration for the labeled chiral centers in this molecule. 4 1 H OH CHOH 12 HyCH H.C HCOCHCI HN a. 1 - R2-R c. 1 =R2- b. 1 - S, 2-S d. 1 - S, 2-R 31

Answer 1

18) Only one of the chiral center is changed and they are not mirror images of each other hence they are distereomers. If both would have changed then they would become enantiomers. So answer is option c) disteromers. 19) Chiral molecules having internal plane of symmetry achiral Answer is option b) 20) Number of stereoisomers 2^n ...where n= # chiral centers in given molecule there are two chiral centers and hence answer is option a) 4 CHз нО .. Answer is option b). Because it contains internal plane of symmetry. 21) 22) Answer is option a) 1-R, 2=R НО° R ОН Н NHCOCHCI2 O2N 23) The given pair is non-superimposable mirror images of each other and hence they are enantiomers. 24) Option b) If you rotate the C-C bond and make eclipsed conformation there is plane of symmetry. Hence meso.

Answer is option b) 25) Нас. H2N S CH3 1 1 26) Priority order is given here. Same priority groups come on same side hence it is "Z" Answer is option b) Z но CH3 2 2 НС Answer is option b) 27) pent-4-ynoic acidOH CHз 28) (2E)-2,5-dichlorohept-2-ene Option d) CНз CI 29) option a) A is more stable than C. 30) Zaitsev's rule predicts that in an elimination reaction, the most substituted product will be the most stable, and therefore the most favored. Answer is option c) 31) Answer is option a) 32) Option d). 33) Option b)