3- Methylhexane, naming

Ethyl precedes methyl in the name therefore 3-ethyl-4-methylhexane is correct... 

Common Name 2-Methylhexane Synonym isoheptane, ethylisobutylmethane Chemical Name 2-methylhexane CAS Registry No 591-76-4... 

Common Name 3-Methylhexane Synonym ethylmethylpropylmethane Chemical Name 3-methylhexane CAS Registry No 589-34-4... 

Systematic name 2,2-Dimethylbutane Systematic name 3-Ethyl-2-methylhexane... 

Systematic name a name composed of syllables defining the structure of a compound e.g.. chlorobenzene. 2-methylhexane. 

One further point of possible confusion is where to locate the numerical symbol for the main functional group in the name. For instance, if the double bond in 1 were absent, we could name the compound either 5-methylhexan-2-ol or 5-methyl-2-hexanol. The rule is to not divide the name unnecessarily. Thus 5-methyl-2-hexanol would be correct and 5-methylhexan-2-ol would be incorrect ... 

The chain is numbered so as to give the lowest number to the substituent that appears closest to the end of the chain. In this case it is numbered so that the substituents are located at C-2 and C-4 rather than at C-3 and C-5. In alphabetical order the groups are ethyl and methyl they are listed in alphabetical order in the name. The compound is 4-ethyl-2-methylhexane. 

The correct numbering shows us that the branch comes from the third carbon atom in the straight chain. Therefore, the hydrocarbon name begins with the number 3. There is one carbon atom in the branch, so the branch name begins with meth- and ends in -y/—methyl. The straight chain has six carbon atoms (hex-) with only single bonds (-ane), so it is named hexane. Put it all together and we have 3-methylhexane. 

Correct name 3-methylhexane the longest chain is 6 carbon atoms. 

Examination of this structure shows that the longest chain has six carbons rather than five. Therefore, the correct name is 3-methylhexane. 

The longest chain of carbon atoms is six. If the carbon atoms are numbered from left to right, there is one methyl and one ethyl group on the third carbon atom. The name of the compound will be 3 - ethyl - 3 - methylhexane. 

Practice Probiem 20.7 A student incorrectly named two compounds (a) 3-methylbutane and (b) 1-methylhexane. Write formulas corresponding to these names, and give the correct names for the compounds. ... 

The product formed in largest amount by the hydrochloric acid-promoted and peroxide-induced reaction of isopentyl chloride with ethylene was also that formed by alkylation at the tertiary carbon atom, namely 1-chloro-3,3-dimethylpentane (Ig.) (Expt. 25). The remaining constituents of the reaction product were all obtained in very minor amount and were all alkyl chlorides. Among these were 4-chloro-2-methylhexane (y), 1-chlorohexane (formed by telomerization) and some chlorononanes including 5-chloro-3,3-dimethyl-heptane (3 ) formed by ethylation of 12, 4-chloro-2-methyloctane (15) and l-chloro-3-methyloctane (IT). ... 

It is incorrect to name the compound 5-methylhexane because that violates Rule 2. 

The methyl group is attached to the second carbon atom in a six-carbon chain, so the compound is named 2-methylhexane. 

All six of these are the same compound. They only differ from each other by rotations about one or more carbon-carbon single bonds. Only one isomer of CjHig is present in all of these names 3-methylhexane. 

Pcnlanc is an iiicorrccl parent name. Correct name is 3-etliyl-2-methylhexane. 

Isoheptane is a common name Note the (CHi)iCH group at the end of an otherwise straight chain. IUPAC name 2-methylhexane. 

Name is incorrect. Numbering should go the other way (right to left), giving 3-chloro-2-methylhexane. 

Name is incorrect. The wrong parent chain has been chosen. Number a six-carbon chain as shown, and then name it 3-ethyl-3-methylhexane. 

In the last structure, the methyl group is on the carbon atom with the lowest number. The name of the compound is therefore 3-methylhexane and not 4-methylhexane. 

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