Naming a hydrocarbon chain with multiple substituents equidistant from both terminals

Does the substituent that comes alphabetically first take precedence, or do we look for the next nearest substituent, or is it a combination of both?


[![this is the compound I am trying to name](https://i.stack.imgur.com/mDNoS.png)](https://i.stack.imgur.com/mDNoS.png)




The substituents in the compound that is given in the questions are not equidistant from both ends.


Numbering from left to right yields the name 5-bromo-3-chloro-7,8-diethyl-2,9-dimethyldecane (i.e. the locant set ‘2,3,5,7,8,9’), whereas numbering from right to left yields the name 6-bromo-8-chloro-3,4-diethyl-2,9-dimethyldecane (i.e. the locant set ‘2,3,4,6,8,9’).


Concerning numbering, the current version of *[Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book)](http://dx.doi.org/10.1039/9781849733069-fp001)* reads as follows:



> 
> **P-14.4** NUMBERING
> 
> 
> When several structural features appear in cyclic and acyclic compounds, low locants are assigned to them in the following decreasing order of seniority:
> 
> 
> (…)
> 
> 
> (f) detachable alphabetized prefixes, all considered together in a series of increasing numerical order;
> 
> 
> (g) lowest locants for the substituent cited first as a prefix in the name;
> 
> 
> (…)
> 
> 
> 


Note that Rule f takes precedence over Rule g.


Furthermore,



> 
> **P-14.3.5** Lowest set of locants
> 
> 
> The lowest set of locants is defined as the set that, when compared term by term with
> other locant sets, each cited in order of increasing value, has the lowest term at the first
> point of difference; (…)
> 
> 
> 


Therefore, the example is named as **6-bromo-8-chloro-3,4-diethyl-2,9-dimethyldecane** rather than 5-bromo-3-chloro-7,8-diethyl-2,9-dimethyldecane since the locant set ‘2,3,4,6,8,9’ is lower than ‘2,3,5,7,8,9’.


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