Q1:- Which of the isomeric alcohols having formula CSH120 are chiral? Which are achiral? Draw the enantiomers.

4. (a) Draw all possible isomers of C4H3CI2. (b) Indicate which pairs of compounds are enantiomers of one another. (c) Indicate which pairs of compounds are diastereomers of one another. (d) Indicate which compounds would have optical rotations of 0°. (e) Assign R and S configurations to all chirality centers of the compounds in part (a).

(9) How many chiral centers are present in a molecule of 1,3-dimethylcyclohexane? (C) 2 (D) 3 1 (A) O (10) What is the percent composition of a mixture of (S)-(+)-2-butanol, [a] = +13.52°, and (R)-(-)-2-butanol, [a] = -13.52°, with a specific rotation [a]D = -6.76° (A) 75%R 25%S (B) 25%R 75%S (C) 50%R 50%S 67%R 33%S

190x3 3.1.2 The conformations of cycloalkanes Construct a model of cyclohexane (C6H12), a six-membered ring of carbon atoms with two hydrogen atoms attached to each carbon atom. Is the ring planar or puckered? 1. (a) 55 (b) The cyclohexane ring can be arranged in many forms. The two major forms are commonly called the chair conformation and the boat conformation. For instance in the chair conformation; consider the two hydrogen atoms at each carbon. One C-H bond is roughly in the mean plane of the molecule and one C-H bond is roughly perpendicular to that plane. These two positions are referred to, respectively, as equatorial and axial, as shown below. axial bond H equatorial bond Hequatorial H axial H wallon (i) Arrange the model in the chair form. Clearly add and label the axial (a) and equatorial (e) hydrogens on the sketch of the chair confirmation below. emend bundano (c) Arrange the model in the boat form. Clearly add and label the axial (a) and equatorial (e) hydrogens on the…

Draw a Newman projection of the synclinal (or gauche) conformation of 1-iodo-2-nitroethane (ICH2CH2NO2).

Determine whether trans-1,2-dimethylcyclopentane contains a chiral center. How many different substituents do you count at atom #(2)?