Study On The Synthesis Of Cyclopropanes And Cyclopropenes

The cyclopropenes play a very important role in the storage of plants and plantsproduct. They can restain an ethylene response effectively and avoid the negativeeffects on plants by binding to plant ethylene receptor sites. These compounds are safeand don't pollute the environment when they are used. Recently it is popular that theresearch of the application of the cyclopropenes. The structure of the cyclopropeneshas the smallest unsaturated ring and the three-member ring strain is very strong. Sothe compounds are unstable. It is also significant in theory that we study on thesynthesis method of the cyclopropenes.In the paper some gem-dibromocyclopropanes were obtained easily from thecycloaddition reaction of dibromocarbene with different olefins, such as styrene,1-methyl-1-phenyl ethylene, stilbene, cyclohexene , 1-hexene. Then thegem-dibrocyclopanes were transformed into the corresponding cyclopropenes by theelimination reaction with the existence of strong base. We also got cyclopropenes bythe rearrangement of carbenes. And we tried to catch the cyclopropenes by usingcyclopentadiene, bromine and β-cyclodextrin. All the compounds were characterizedby IR, 1H NMR and GC-MS.Furthermore, 2,5-Bis(1-piperidinylmethyl)benzene-1,4-diol andN,N,N',N'-Tetrabenzylethylenediamine were synthesized and the single-crystal X-raydiffraction measurements of the two compounds were carried out in order to elucidatethe structures.