2-Ethyl-2-hexene

Draw structures for these compounds a) 3-Ethyl-3-hexene b) Cyclobutene c) 3-Propyl-cyclohexa-1,4-diene... 

C8H16 3-ethyl-3-hexene 16789-51-8 389.15 33.317 1,2 15072 C8H160 3-ethyl-4-methyl-2-pentanone 71172-57-1 427.65 35.903 1,2... 

We could number either chain from the other end and still have the double bond starting at carbon 3 we number from the end that gives the carbon bearing the ethyl group the lowest possible position number, 3. Carbon 3 has two equivalent substituents, so geometric isomerism is not possible, and we do not use the cis-trans terminology. The name is 3-ethyl-3-hexene. 

Determine whether each of the following molecules can exist as cis-trans isomers (1) 1-pentene, (b) 3-ethyl-3-hexene, and (c) 3-methyl-2-pentene. 

If two sets of reagents are available for the synthesis of an alkene, it is better to use the one that requires the less sterically hindered alkyl halide for synthesis of the ylide. Recall that the more sterically hindered the alkyl halide, the less reactive it is in an Sn2 reaction (Section 10.2). Eor example, it is better to use a three-carbon alkyl halide and a five-carbon carbonyl compound than a five-carbon alkyl halide and a three-carbon carbonyl compound for the synthesis of 3-ethyl-3-hexene because it would be easier to form an ylide from 1-bromopropane than from 3-bromopentane. 

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