Question

1. State the systematic (IUPAC) name for each of the following compounds. (12 points): a) OH b) 0: :OH

Answer 1

a)) First of all, you have to select the longest chain of carbon and number them in such a way that the functional groups present get the lowest numbering. Now for the first molecule, the longest chain contains 6 carbons. So, parent name will be Hexane. Now, if you start numbering from extreme left, the hydroxy group gets on number 2 whereas if you start numbering from extreme right hand side, the aldehyde group gets on number 1 carbon.

Hence, the name of the compound will be 5-hydroxy-2-oxohex-3-enal.

b)) In this case also, select the longest chain of carbon atoms and find the parent name. The longest chain contains 6 carbon atoms, hence, again, the parent name will be hexane. Now, a functional group always has higher priority than the double bond or the triple bond. Hence, in this case, numbering will start from extreme left hand side.

Hence, ther name of the compound will be 4-methylhexa-2,5-diynal .

c)) In this case too, select the longest chain of carbon atoms and that will give you the parent name.In this case too, longest chain of carbon atoms contains 6 atoms, hence, parent name will be hexane. Now, in this case, numbering will start from extreme left so as to give the double bond the lowest numbering as shown :-

e) 7 OH Numbering

Hence, the name of the compound will be 4-chloro-3-hydroxyhex-1-ene.

Thanks and best wishes.