Seven-carbon chain

Analogues with a seven-carbon chain connecting the phenyl and isoxazole rings, and with a substituent on the oxazoline ring, were bound with the isoxazole ring in the toe of the hydro-phobic pocket. 

Wamelink MM, Smith DEC, Jansen EEW, Verhoeven NM, Struys EA, Jakobs C (2007) Detection of Transaldolase Deficiency by Quantitation of Novel Seven-Carbon Chain Carbohydrate Biomarkers in Urine. J Inherit Metab Dis 30 735-742... 

Answer (b). It is preferable to keep the names as short as possible. So rather than repeating methyl twice, it s more efficient to say dimethyl which means two methyls. The numerals indicate where these methyls are attached. Also, note that the naming is based upon the longest chain, which is eight carbons. Answers (c) and (d) are based upon a shorter seven-carbon chain, where the suffix -kept means seven. 

Rule 1. Choose as the fundamental chain of a formula the longest chain containing the maximum number of double bonds — for example, choose the eight-carbon rather than the seven-carbon chain for myrcene (No. 2, Chart 3). The longest chain chosen by this rule may not necessarily be the longest chain in the molecule. 

The groups attached to the main chain are called substituents because they are substituted (in place of a hydrogen atom) on the main chain. When there are two longest chains of equal length, use the chain with the greater number of substituents as the main chain. The following compound contains two different seven-carbon chains and is named as a heptane. We choose the chain on the right as the main chain because it has more substituents (in red) attached to the chain. 

The deoxy-northern half C7-C15 is barely functionalized apart from the marginal connection points, i.e. the central C8 to C14 area contains only a double bond with imperative cis configuration and one stereocenter at C8 (instead of three in the final target). Possible disconnections are much less predetermined than in the C1-C7 aldol-region . Therefore all six C-C-bonds within the seven-carbon chain from C8 to CI4 were used as strategic bonds. 

Compounds with two double bonds are named as dienes by changing the -ane ending of the parent alkane to the suffix -adiene. Compounds with three double bonds are named as trienes, and so forth. Always choose the longest chain that contains both atoms of the double bond. In Figure 10.1, the alkene is named as a derivative of heptene because the seven-carbon chain contains both atoms of the double bond, but the eight-carbon chain does not. 

Figure 2.1.3. A seven-carbon chain twisting about its bonds.

Macrocyclic diarylheptanoids can be derived from linear ones by oxidative cyclization. This is supported by the fact that in all of the biaryl type representatives the aryl-aryl bond is in meta position relative to both ends of the seven-carbon chain, while in those containing a diarylether bond a meta,para bridging can be identified. This substitution pattern corresponds to activation of the position ortho to the phenolic hydroxy group. Biosynthesis of cyclic diarylheptanoids was investigated by Inoue et al. (84). They fed [1- C] and... 

Because the molecule has a seven-carbon chain, you use the prefix hepta-. Because it has two double bonds, you use the prefix di- before -ene, giving the name heptadiene. Adding the numbers 2 and 4 to designate the positions of the double bonds, you arrive at the name 2,4-heptadiene. 

The root name heptane indicates that there is a seven-carbon chain. 

The strucmre is based on a seven-carbon chain with a triple bond beginning at carbon 2. We add methyl groups at the positions indicated. 

The root of the name of a seven carbon chain is hept- ... 

Analysis The longest chain contains seven carbons, so this is a heptane. However, there are two ways to identify a seven-carbon chain (sec numbering). Which one is the parent The rules specify that, in case of a tie for longest chain, the one with the most substituents is chosen as the parent. The seven-carbon chain labeled a has one sub.stituent (a jbutyl group on carbon 4). The seven-carbon chain labeled b has two substituents (a methyl on carbon 3 and a propyl on carbon 4),. so it wins. The molecule is called 3-methyl-4-propyl-heptane. 

Ans. (a) The longest continuous chain that contains the carbon holding the OH is the seven-carbon chain numbered as shown below ... 

Molecular model 20A shows that the two hydrogen atoms on one terminal carbon (the CH2 unit) are perpendicular to the hydrogen atoms on the other terminal carbon (the other CH2 unit). The electron density map of allene (see 20C) shows the higher concentration of electron density (red color) is between the carbon atoms, but in different planes. This model confirms that the two 7t-bonds are perpendicular to one another. Substituted allenes are also named as dienes. For example, compound 21 has the C=C=C unit as part of a seven-carbon chain, so it is a heptadiene. Giving the cumulative diene unit the lower numbers leads to 2-methyl-2,3-heptadiene as the name for 21. 

With this numbering scheme, the substituent is at C3, so 18 is named 3-hep-tyl-2, 4-hexanedione. In 19, the two ketone units are part of the ring, and the name is 1,3-cyclohexanedione. Dialdehyde (dial) 20 has both carbonyl carbons in a six-carbon chain, so it is a 1,6-hexanedial. Numbering the substituents accordingly leads to 2-ethyl-5-methyl-l,6-hexanedial. For 21, there is a seven-carbon chain and, because the aldehyde unit takes priority, it is a heptanal. Naming 21 as an aldehyde means that the aldehyde carbonyl is carbon-1, so the ketone carbonyl is at C5. The name of 21 is 5-oxoheptanal. 

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