This document discusses nomenclature for bridgehead heterocycles. It notes that the two carbons forming each bridge will always be cis to each other, and both hydrogens will be on the same side. It also notes that both bridgehead positions are on the same carbon, so bicyclo nomenclature cannot be used, but the process is similar - substitute "spiro" for "bicyclo", insert the two bridge lengths, and use the same suffix as before.

1. Nomenclature of bridge
head heterocycles
Dr Taj Khan
Dept. of Pharmaceutical Chemistry, OCP,
Sanpada, New Mumbai.

3. Two carbons forming each bridge will always be “cis” to each other
Both hydrogens are on the same side

7. Both “bridgehead” positions are on the same C, so cant use “bicyclo” nomenclature as before-
but the process is very similar.
simply substitute “spiro” for “bicyclo” , insert the two bridge lengths, and place the suffix as before.