Spiro junction

A-42.1, but the spiro junction has priority for lowest numbers over un-saturation. 

The development of electronic circuity will require the relative positioning of components. This has been investigated, for instance, through orthogonal connection of two oligothiophenes via spiro junctions (e.g., 106) [8.158, 8.159]. Electron... 

Gardmultine (C45H54N4O10) a bisindole alkaloid isolated from Gardneria multiflora Makino, comprises gardneramine and chitosenine linked by a spiro five-membered ring. The structure proposed from chemical and spectroscopic properties (50) was confirmed by the crystal-structure analysis (51). The structural formula and the stereodrawing, shown in Fig. 25, illustrate the spiro junction at atom C-16 between the two component alkaloids of gardmultine. 

Other chiral geometries are also possible, e g. those that possess perpendicular disymmetric planes. Optical activity will occur if there are two rings that contain an even number of atoms joined in a spiro manner, with each ring substituted at the carbon furthest from the spiro junction. In this case, an elongated tetra-hedron is formed. 

Amorphous thin films of spiro-linked compounds (14a-d) (Figure 3.1.5) have been tested in OTFTs.[107,108] The characteristic structural feature of these materials is the linkage of two hole transporting units by a spiro junction. A mobility of 7 X 10 cm V s was obtained with an on/off ratio of 10 . 

Simmons-Smith reaction is directed by the hydroxy function, the configuration at the spiro junction may be controlled at will by selecting the appropriate epimer of the starting allylic alcohol. 

In 2008, Cipolla and Nicotra, focused on the synthesis of conformationally constrained l,4-benzodiazepine-2,5-diones (97-101), containing both a monosaccharide, fructose and a proline moiety (Fig. 28). ° The D-proline moiely is connected to fructose through a spiro junction that provides a high conformational rigidity. 

Oligomycins. The three-dimensional structure of oligomycin B has been determined, and the molecule is composed of a 26-membered ring to which is condensed a substituted tetrahydropyran ring which in turn is linked to another tetrahydropyran ring by a spiro-junction see (105). ... 

A spiro junction exists when two rings are connected through a single (carbon) center. Monospirocycles containing only two aliphatic rings are specified by the term spiro in front of the name of the corresponding acyclic system with the same number of carbon atoms. To discern possible... 

Linear polyspiro compounds of this kind are identified as dispiro-, trispiro- etc. -alkanes here too the numerical descriptors are obtained by enclosing the sums of atoms between the spiro centers in square brackets and separating them by full stops. The smaller peripheral ring is numbered first, and smaller numbers are preferred for the internal path lengths. This leads automatically to smallest possible locants for spiro centers when overall numbering starts on the smaller outer ring at a C atom next to the first spiro junction. 

If a partial structure appearing in a spiro compound already posseses an indicated hydrogen, this hydrogen is placed directly in front of the component name, preceded by its locant and enclosed in square breckets, if necessary. If, however, spiro junction is only possible after a formal dihy-... 

Spiro systems in which the spiro atom is at the same time incorporated into a third ring - i. e., where the spiro junction is not free - are not named as spiro compounds but treated as fused polycycles. 

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