Question

Q11. The correct structure of trans-1-bromo-3-methyl cyclopentane is ...Br (A) (B) -Br Br (C) (D) *Br Q12. The correct order of increasing stability for the following conformations is CH, H Н. Н H H H CH2CH3 H Н CH,CH CH CH3CH2 CH H2C CH, H CH, I II III (A) III < III (C) II <I<III (B) I<III <II (D) I< II < III

Answer 1

from so, - Brand --ME 11. Br tremsed-bromo-3-methyleyebpentana here as the.com:ligeration is pancre in-apposite pas face. [B] So, the correct- mower in (B). Memo H H1 12. H H el3 CH2-CH3 Bene CH3 CH3 TC here the two methyl here the tro additional but ane gauche gooups are in trom position. omd here gauche interaetion between the butane interaction. one in methyl methyl and the other in methyl- ethyl interaction methyl and ethyl group. I -H H CH₃ 20. GH₂ CH₃ In the structure in the ethyl Не ond metal ore in straggered x position. And one odditiond butone gauche interaction between two methyl groups. methyl-methyl intention internation so it in more stable than I. And I intent- stable as there are two gauche interaction. so, Stability :- TIL > I > II : Comeet answer | here methyl-ethyl

13. Hža CH eh front Carbon brotated CH by 1200 6+3 I H HC Ciriclockwiz le he liben we rotate the food Carbon G the I in Herman protection by 196° antieboek- Wire, then we get exact I structure. 30, I and I are the different conformations of the same compormd. E. correct answer (D) Ch 14, When both the substituents are in axial position then the extent o 13 diccial interaction is most. so, the compound become lest stable I one axial both equatorial 50, most stable sono diancial intercetin Substituent So, ene 1,3-diencia! interaction TIL thro arial substituent So, two diaxial intercation 5o, Least stable one axial substituent hence one diarial intercetion So, the least stable structure is lll.

15. CH3 CH3 CA 2 До CH3 3 -CH3 2 So, from the contormation heres thet, tromethyl groups are equalize ma those are at c-2, and .e-1. And the methyl group in C4 in ariel. Sto, correct answer (D) 1 . -