Question

TU c) Start with the model of propene built in 3a), substituting different hydrogen atoms of propene with a methyl group to form isomers of butene, CaHg. How many different isomers exist for butene (C4Hg)? Prepare models and draw the Lewis structures for each of the isomers. d) Two of isomers of butene comprise a pair of stereoisomers. Draw the skeletal structures and include IUPAC names for the cis and trans isomers. Recall in the cis isomer both methyl groups are on the same side of the double bond; in the trans isomer they are on opposite sides. 3. Cyclic compounds The presence of the ring in all but very large ring cyclic molecules prevents full rotation of the ring atoms. For this reason, stereoisomerism may also occur in cyclic molecules. a) Prepare a model of cyclohexane, C6H12. Draw the condensed formula. b) Build a model of methylcyclohexane (C7H14) by replacing one of the hydrogens of cyclohexane with a methyl group. Draw the skeletal formula for methylcyclohexane.

Answer 1

CH3 Leon H3C CH2 propene 4 different isomers of Butene are as follows: Н Н H H H Н. H Н. H H butene 1 2 (E)-but-2-ene H H H CH3 H3C 3 (Z)-but-2-ene 2-methylprop-1-ene Structure 2 and 3 are geometrical isomers. d) Stereoisomers of butene H H H H H th H c H (Z)-but-2-ene (E)-but-2-ene Trans isomer Cis isomer

3.a) Condensed formula of cyclohexane: H2C CH2 H2C CH2 H2 cyclohexane (Condensed formula) Skeletal formula of cyclohexane b) Skeletal formula of methylcyclohexane: CH3 H2C CH2 H2C CH2 H2 Condensed formula of methylcyclohexane methylcyclohexane (Skeletal formula)