A Study On Synthesis Of Substituted Cyclopropyl Compounds And Their Ring-opening Products

As an important kind of organic compounds, cyclopropyl compounds have a wide range of applications in medicine, pesticide and other industries for its good biological activity and selectivity of the strucure-activity groups. At present, there have been many methods to synthesize cyclopropyl compounds, but we adopted nucleophilic substitution reactions and carbene reactions considering the yields and the ease of access to raw materials.At the same time, cyclopropyl compounds are unstable and easy to be open-loop and alcohols are prone to proceedingβ-elimination to produce alkenes, therefore cyclopropyl alkanols are prone to proceeding ring-opening elimination to get high homoallylic halides which have the dual natures of alkenes and halides and are important intermediates in organic synthesis. High homoallylic halides were synthesized by the ring-opening elimination reaction of cyclopropyl alkanols in this paper.The main research work of this paper was divided into two aspects:Ⅰ: The research of the synthesis of cyclopropyl compounds(1) We took the nucleophilic substitution reaction to synthsize cyclopropyl ketones compounds, then used the format reaction to prepare cyclopropyl alcohol compounds.We discussed the influencing factors and accessed a mild reaction conditions and high yield synthetic route.(2) The cyclopropyl carboxylate that was the first Ju-ethyl compounds was synthesized through the carbene reaction.(3) The cyclopropyl dicarboxylic acid was obtained by using the acetone and dichloromethane as solvents, the first Ju-ethyl as raw material and the potassium permanganate as oxidant. The reaction conditions of the method of dichloromethane as solvent were aslo discussed, in this method the phase transfer catalyst was used, the yield was improved and the amount of sulfuric acid was reduced, it is friendly to the environment.(4) According to the character that o-dicarboxylic acid is easily dehydrated to form a more stable five-membered ring, we used acetic anhydride as dehydrating agent and cyclopropyl dicarboxylic acid as raw materials to prepare the biological activity cyclopropyl anhydride: 6,6-dimethyl-3-oxa-bicyclo[3.1.0]hexane- 2,4-dione.Ⅱ: The research of cyclopropyl alkanol's ring-opening product (high homoallylic halides )A series of high homoallylic halides were synthesized by the open-loop system of cyclopropyl alkanols and halogen acid under different reaction conditions. This method is simple, the raw materials are readily available, the reaction time is short and the yield is high and alkenes have the character of cis-trans isomerization.The structures of the synthesized compounds are confirmed by 1~H-NMR, (13)~C-NMR and several other means. In this paper, 1-cyclopropyl-1-methyl butanol, 1-cyclopropyl-1-methyl pentanol, 1-cyclopropyl-1-benzyl alcohol, 1-chloro- 4-methylhept-3-ene, 1-chloro-4-methyloct-3-ene, 5-chloro-2-benzylpent-2-ene, 1-bromo-4-methylhept-3-ene, 1-bromo-4-methyloct-3-ene, 5-bromo-2-benzylpent- 2-ene, 1-iodo-4-methylhept-3-ene, 1-iodo-4-methyloct-3-ene and 5-iodo-2-benzylpent- 2-ene were synthesized, which were not reported before.