Answer
a) 3-chloro-1-butene
b) 1-ethyl-3-methyl-1-cyclopentene
c) 4-chloro-3-propyl-1-cyclopentene
d) 1,2,4-trimethylcyclohexane
e) o-bromotoluene
f) 2-bromo-1-methylcyclohexane
g) 4-bromo-3-methyl-1-cyclohexene
Work Step by Step
a) No. of C in straight chain = 4. hence, root name is 'but'. Now, here one substituent 'Cl' and one double bond is present. numbering of straight chain C atoms is done so that double bond will get the minimum number. So, numbering is done from right side. double bonded C gets C1 position and Cl atom present in C3 position. So, '3-chloro' is added as prefix and 1 is added before root name 'but' and ending name is 'ene' for alkene.
b) no. of C in ring = 5. so, the root name is 'cyclopent'. Now, there is a double bond in the ring Carbons. Numbering is done so that double bonded C atom gets C1 position. one ethyl group is present at C1 position and one methyl group is present at C3 position if we numbering clockwise. so, '1-ethyl-3-methyl' is added before root name. ending name is 'ene' as there is double bond present in the compound.
c) no. of C in ring = 5. hence root name is 'cyclopent'. now, double bonded C gets the preference i.e. numbering is done so that double bonded C gets the minimum number. So, double bonded C gets C1 position , propyl group is present at C3 position and chlorine group is present at C4 position (propyl gets preference over chlorine) if we numbering anticlockwise. '4-chloro-3-propyl' is added before root name and ending name is 'ene' for alkene.
d) no. of C in ring = 6. hence root name is 'cyclohex'. Numbering the ring C is done from 1 to 6. hence, three methyl substituents are present at C1, C2 and C4 positions respectively. so, '1,2,4-trimethyl' is added before root name and ending name is 'ane' for alkane.
e) one methyl group is present at the benzene ring is named as toluene. Now, a 'Br' atom is present at the ortho position to methyl group. So, the name is o-bromotoluene.
f) no. of C in ring = 6. hence root name is 'cyclohex'. Numbering the ring C is done so that methyl substituent gets preference. hence, numbering is done clockwise and the methyl group will be present at C1 position. So, '2-bromo-1-methyl' is added before root name and ending name is 'ane' for alkane.
g) no. of C in ring = 6. hence root name is 'cyclohex'. numbering the ring C is done so that double bonded C atom gets C1 position. So, numbering is done clockwise so that methyl is present at C3 position and bromo group is present at C4 position. '4-bromo-3-methyl' is added before root name and ending name is 'ene' as there is double bond present in the cycloalkene.
