Question

After siting down the C(2)-C(3) bond in the Newman projection of butane, which is the anti conformation? нус H3C CH, Н. CH, н Н н Сн, H- H Н Сн; н Н (а) (b) H н Н (c) HC CH СН. H H H H H- H H H Н CH; Hс н Сн, a. a Obb Сс с Cd. d е. е f, f

Answer 1

cord c-CH₃ bond are called gauche conformation. un Explanatis : Structure aris arising У X 6=60 & from notation about single bonds (or: flipping of lengs) are colled. Conformations The dihedral angle (0) is the angle between the x-c-e Plane and the C-C-y plane of an X-C-c-y unit in a molecule. In newmann Projection formula, it is the angle between the c-x bond on the front carbon atom and the c-y bond on the back carbon atom. When dihedral angle of butane may be onöthin the range 0° to 360°, + 60° Cor 60ʻf 300°) two root when dihedral angle CH3 60° ceta H ♡ Gauche H H H! Here @ When dihedral angle op between two C-CH3 bond * CH3 then the conformation is fully reclipsed; 120 then called Skew eclipsed and 240° theri also skew eclipseel Open H H Here oplim (e) H (Skew eclipseo) th City ut -CH3 and option @ H H eclipsed.Co - dihedral angle (9) =09) H H

between two e-eltz When the dihedral angle bond is 180° then it is called anti con formation. City H H 4 anti conformation H CH₂ Here option @ bhi In this question the conforation, Option utz and aption (f) Ut3 H H HS (b) H Utz utz H H H are not in the Cg - lz bond in Newmann bond in Newmann projection. y So the correct answer of woo Newmann projection butane moleinte in C2-C3 axis h..option. d) of .ltz H H H H City dihedral angle (0)=180° Anti conformation of butane in C2-C3 aris; a To illustrate the Conformation of all C2-C3 an is we may draws

between two e-eltz When the dihedral angle bond is 180° then it is called anti con formation. City H H 4 anti conformation H CH₂ Here option @ bhi In this question the conforation, Option utz and aption (f) Ut3 H H HS (b) H Utz utz H H H are not in the Cg - lz bond in Newmann bond in Newmann projection. y So the correct answer of woo Newmann projection butane moleinte in C2-C3 axis h..option. d) of .ltz H H H H City dihedral angle (0)=180° Anti conformation of butane in C2-C3 aris; a To illustrate the Conformation of all C2-C3 an is we may draws

TO The chemical formulae of Butane is. 2 3 4 CH3 - CH₂ - CH₂ - CH₂ (normail Butune) Suppose 'we assume than? Ĉ,2 Backside Quibon and 0-3 is the front side carbon Newmann Projectin of n-but'ane w CH₃ CH H Rotate H 60° H H 60 и CH H H Rotate the back side Carbon CH3 H CH3 Anti Skew Eclips CH3 H IH CH3 H Gauche Rotate 600 "CH!! ki City 600 Ratate Fully Felipsed CH3 CH3 H H. I I 60° Rotate H Eclips Sken Is H City Gauche og CH3 60 ° Rotale litz H Anti H atz!