Question

1. a. (4 points) Draw the dash-wedge structure of (2R,3S)-2,3-dichloropentane. b. (4 points) Draw the Fischer projection of enantiomer of the compound drawn in part a. Name the enantiomers. c. (6 points) Draw the Newman projections (looking down the C2-C3 bonds) of the diastereomers of the compound drawn in part b. Name the diastereomers.

Answer 1

Sol:

The solution of the given question is as follows:

• In wedge-dash model R=clock wise rotation, S= Anticlock wise roatation.
• In Fishcher Projection horizontal line = above plane, vertical line= below plane.
• In Newman Projection ${\color{Green} \Theta }$ =0 degree for Eclipsed , ${\color{Green} \Theta }$ =60 degree for Staggered and ${\color{Green} \Theta }$ = angle between 0 to 60 degree for Skew Conformation.
  Sol: 1. @. GR. 3) - 2,3- vdichloro pentane *k chiral center CL → To assign the R and s notation to cherrel centey we hoe to decide the priority order finst. Atom howing high atomic number get the highest priority. Atoms Priority • Cist H-yth Why CA In these two and me howe I cand IH and 3nd one howe 34 ..{chaly cz C-M43 → Antidock wise notation
  
  12 * Sol: Anti-clockwise clockwise notation notation G=963 3 og 3 Anti R clockwise Sopp. like clock's But here, at c-2, H is vabove plane. Howy hand fabove plaene, men t below plane ] .. S configuration changes to R because the lowest priority group (here ) should always be below the plane, otherwise just reverse the configuration, you find at first
  
  Sol: Like chiral center at caribon-3 on C-3 EU-I ce Anticlockwise rotation ..s And here te lowest priority group below plane configuration recyain as it is". Prionity onder cl > CHCl)> CH3 > 1 2 3 Thees, this is vell about dash wedge structure of QR. 3) - 203 - dichloro-pentane.
  
  Fischer projection of (PR, 85)-213-dichloropentane 1 се Ccl LCOH cercah C-2 MS C-3 GM5 B (2R, 35) {Enantioma-(2 8, 3R) the configuration Similarly we can determined fon compound
  
  cu Ce can C2H5 (2R, 35) 9 (25, 3R) A . Mimos plane Ⓡ. → mimom image to each other non super imposable .: Both are enantiomers
  
  @ Newman projection. cetta cat Hotel I - IX Xiastereomers 1-0, IV Neither nitros image non super- emposable H HEE EMS EMS Ets SMS T) 3 23.3R) R2R) QS. 35) Enantiomers neys TERR, 2) HTCM 200 mg C2HS . staggered Eclipsed Skew 0 : angle between co-60)