Answer
a) 1-iodocyclopropane
b) 2-chloro-1,3,5-trimethylcyclohexane
c) 2-chloro-1-ethylcyclopentane
d) 1-ethyl-2-methyl-1-cyclopentene
Work Step by Step
a) No. of C in ring = 3. So, the root name is 'cycloprop' and ending name is 'ane' for alkane. Now, one iodo group is present at C1 position of ring C. So, 1-iodo is added before root name. So, the complete name: 1-iodocyclopropane.
b) No. of C in ring = 6. So, the root name is 'cyclohex' and ending name is 'ane' for alkane. Now, numbering the C atoms in ring will be done so that substituents get the minimum position. Here, four substituents are present i.e. three methyl group and one chloro group. Methyl will get preference over chloro group. So, numbering is done so that three methyl groups get the C1, C3 and C5 position respectively and one 'Cl' group gets the C2 position. So, '2-chloro-1,3,5-trimethyl' is added before root name. Complete name : 2-chloro-1,3,5-trimethylcyclohexane.
c) no. of C in ring = 5. hence, the root name is 'cyclopent' and ending name is 'ane' for alkane. now, numbering of ring C will be done so that the substituents get the minimum position. Here, two substituents are present i.e. ethyl and chloro group. Ethyl group gets preference over chlorine atom. So, ethyl group is present at C1 position and chlorine is present at C2 position. '2-chloro-1-ethyl' is added before root name. So, the complete name: 2-chloro-1-ethylcyclopentane.
d) no. of C in ring = 5. hence, root name is 'cyclopent' and ending name is 'ene' as there is a double bond present at C1 position. Now, numbering of ring C is done so that ethyl group gets C1 position and methyl group gets C2 position (alphabetically ethyl group gets preference over methyl group). So, '1-ethyl-2-methyl' is added before root name and we get the complete name i.e. 1-ethyl-2-methyl-1-cyclopentene.
