Question

Be sure to answer all parts. Give the IUPAC name for the following compound. 1 Wathynyl athynyl methylcyclohexene

Answer 1

According to IUPAC nomenclature, alkenes get priority over alkynes hence in the name 'ene' come as suffix and 'yne' present as prefix Since the longest carbon chain has 6 carbons in cyclic form, rootword is 'cyclohex' 1-ethynyl-6-methylcyclohexene 1-ethynyl-6-methylcyclohex-1-ene since the numbering started from the alkene double bond one can write name as 'cyclohex-1-ene' too.

The IUPAC name of the any compound contains 3 parts prefix+ rootword + suffix Prefix = any substitutents rootword = longest chain containing most number of carbons if the chain contains 1 carbon = meth 2 carbon = eth 3 carbon = prop 7 carbon = hept 4 carbon = but 8 carbon = oct 5 carbon = pent 9 carbon = non 6 carbon = hex and so on Suffix = if the compound contains single bond (C-C) only then suffix 'ane double bonds (C=C) 'ene triple bonds 'yne For selecting prefix numbering, the substituents numbers has to be given in such way that the sum of the all substituents should be as less as possible. For selecting rootword chain, the chain with more number of carbons has to be selected In all the given compounds alkanes are present, hence the suffix is 'ane' in all the four compound For all the compounds, blue coloured part of the name is prefix. red coloured part of the name is rootword and pink coloured part of the name is suffix