Why is ethoxyethane the preferred IUPAC name for diethyl ether rather than 1,1'-oxydiethane? Diethyl ether has a few systematic names. Its preferred IUPAC name is generated using substitutive nomenclature: ethoxyethane. But multiplicative nomenclature could be used, in the symmetric spirit of its common name, to generate the name 1,1'-oxydiethane. The Nomenclature of Organic Chemistry 2013 (blue book) makes it clear that multiplicative nomenclature is preferred to substitutive. So why is the preferred name substitutive?

The book says these about multiplicative nomenclature:


P-51.1.5: “Multiplicative nomenclature (P-15.3, P-51.3), as a subset of substitutive nomenclature, is preferred to simple substitutive nomenclature when the criteria for its use are met…”
P-51.3: “Substitutive nomenclature is used when the conditions for constructing multiplicative names are not met.”
P-51.3.1: “Multiplicative nomenclature is preferred to substitutive nomenclature for generating preferred IUPAC names to express multiple occurrences of identical parent structures other than alkanes when
“(1) the linking bonds (single or multiple) between the central substituent group of the multiplicative group and all subsequent structural units are identical and
“(2) the multiplicative groups, other than the central multiplicative group, are symmetrically substituted; and
“(3) the locants of all substituent groups on the identical parent structures, including suffix groups, are identical.”
The deciding criterion is in the preamble to P-51.3.1, not in the numbered criteria: “other than alkanes.” The identical parent structure in diethyl ether is a straight-chain alkane, so multiplicative nomenclature does not apply.