Identical side chain

When a cyclic component carries more than one identical side chain, the name of the cyclic component is followed by di-, tri-, etc., and then by the name of the acyclic component, and it is preceded by the locants for the side chains. Examples are... 

When side chains of two or more different kinds are attached to a cyclic component, only the senior side chain is named by the conjunctive method. The remaining side chains are named as prefixes. Likewise, when there is a choice of cyclic component, the senior is chosen. Benzene derivatives may be named by the conjunctive method only when two or more identical side chains are present. Trivial names for oxo carboxylic acids may be used for the acyclic component. If the cyclic and acyclic components are joined by a double bond, the locants of this bond are placed as superscripts to a Greek capital delta that is inserted between the two names. The locant for the cyclic component precedes that for the acyclic component, e.g., indene-A - -acetic acid. 

The two 2-chloro-4,6-bis(alkylamino)-s-triazines with identical side-chains,... 

The question of tolerability of penicillins, monobactams, and carbapenems in patients with IgE hypersensitivity to cephalosporins was recently assessed in 98 subjects by serum IgE antibody assays, challenge tests, and skin testing with penicillin reagents, aztreonam, imipenem-cilastatin, and meropenem. Approximately 25 % of cephalosporin-allergic subjects were positive to penicillins, while 3.1,2, and 1 % showed positive results to aztreonam, imipenem, and meropenem, respectively. A reaction to a cephalosporin with a similar or identical side chain to penicillin was a sigifificant predictor of cross-reactivity. For skin testing, the following concentrations were used ampicillin and amoxicillin 1 and 20 mg/ml cephalosporins 2 mg/ml aztreonam 2 mg/ml imipenem-cilastatin 0.5 mg/ml and meropenem 1 mg/ml. 

While enantioconvergent as well as divergent sequences at any rate need chiral starting materials, the very useful and highly efficient differentiation of enantiotopic groups asks only for prochiral compounds, as for instance 325. To arrive at pure enantiomers, one of the two structurally identical side chains of the starting material 325 has to be attacked enantioselectively, as is demonstrated with the Sharpless oxidation, which in this case leads to epoxide 326 as the main reaction product [115]. 

The tricyclic structures of TCOC and TCPOC are obtained by consecutive radical reactions via five reactive sites in colupulone, namely C-4, C-12, C-13, C-17 and C-18, respectively. Alternative structural representations are either sterically impossible or not in agreement with the spectral data. For the same reasons, other regio-isomers can be rejected, while intramolecular reactions between the identical side chains at C-6 can also be excluded. 

Identical side chains are indicated by the multiplicative prefixes di, tri, tetra,penta, etc. If side chains with identical further substituents are present the multiplicative prefix forms bis, tris, tetrakis, pentakis, etc. are employed. (The prefix forms bi, ter, quater, quinque, sexi, septi, etc. are reserved for direct linking of identical units see the following Sections.)... 

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