SPIRO COMPOUNDS

SP-1 Compounds with only monocyclic ring components
SP-1.1 Monospiro hydrocarbons with two monocyclic rings are named by the prefix spiro before a von Baeyer descriptor (indicating the numbers of carbon atoms linked to the spiro atom in each ring in ascending order and separated by a full stop) placed in square brackets and then the name of the parent hydrocarbon indicating the total number of skeletal atoms e.g. spiro[4.4]nonane.
SP-1.2 Monospiro hydrocarbons with two monocyclic rings are numbered consecutively starting in the smaller ring at an atom next to the spiro atom, proceeding around the smaller ring back to the spiro atom and then round the second ring.
Example:


spiro[4.5]decane
not spiro[5.4]decane

SP-1.3 Heteroatoms are indicated by replacement prefixes (rules B-4.2, B-6.1, 5 and rules R-1.2.2.1 and R-9.3, ref 6) and unsaturation is indicated in the usual way (rule A-11.3, ; R-3.1.1, ) by the endings ene, diene, etc.

Examples:


8-azaspiro[4.5]dec-2-ene

spiro[4.4]nona-2,7-diene

3,9-diazaspiro[5.5]undecane
SP-1.4 Unbranched polyspiro hydrocarbons composed of only monocyclic rings are named using dispiro-, trispiro-, etc. indicating the total number of spiro atoms present and the name of the parent hydrocarbon corresponding

NAMING OF BICYLO ORGANIC COMPOUNDS

Bridged Hydrocarbons

Rule A-1. Bicyclic Systems
1.1 - Saturated alicyclic hydrocarbon systems consisting of two rings only, having two or more atoms in common, take the name of an open chain hydrocarbon containing the same total number of carbon atoms preceded by the prefix "bicyclo-". The number of carbon atoms in each of the three bridges connecting the two tertiary carbon atoms is indicated in brackets in descending order.

Examples to Rule A-1.1

1.2 - The system is numbered commencing with one of the bridgeheads, numbering proceeding by the longest possible path to the second bridgehead; numbering is then continued from this atom by the longer unnumbered path back to the first bridgehead and is completed by the shortest path from the atom next to the first bridgehead.

Examples to Rule A-1.2

1.3 - Unsaturated hydrocarbons are named in accordance with the principles set forth in Rule A-11.3 When after applying Rule A-1.2 a choice in numbering remains unsaturation is given the lowest numbers.

Examples to Rule A-1.3

(See Rule A-.1 for double locants)

1.4 - Radicals derived from bridged hydrocarbons are named in accordance with the principles set forth in Rule A-11 The numbering of the hydrocarbon is retained and the point or points of attachment are given numbers as low as is consistent with the fixed numbering of the saturated hydrocarbon.

Examples to Rule A-1.4