Simple Synthesis Of 3-oxa-bicyclo[3.1.0] Hexane Derivatives

Vinyl cyclopropane compounds with a high degree of reactivity in organic synthesis plays an important role for increasing attention. First, the formation of vinyl cyclopropaneΠ-allyl-metal intermediate, followed by a series of reactions, the main reactions: addition reaction, cycloaddition reactions, ring isomerization reaction, metathesis, etcRecently, our team based on easy to get a dual activation of cyclopropane derivatives in stannic chloride-catalyzed ring-opening / re-cyclization domino reaction of highly selective, step and efficient synthesis of furan and quinoline alkaloids, to build a natural product Martinelline molecular skeleton .In our thesis we report a novel method for the synthesis of the tricyclic core of Martinellic acid.β-Hydroxymethylcyclopropanylamides have the structure characters of both cyclopropyl amides, and cyclopropyl carbinol. On treatment with an acid, cyclopropyl carbinyl cation intermediate could be formed from cyclopropyl carbinol. This carbocation will undergo either ring expansion to give a cyclobutyl cation or ring cleavage to give a homoallyl cation to relieve ring strain.In addition, the active methylene compounds and 2,3 - dibromo-propionamide to build a domino reaction of 3 - azabicyclo [3.1.0] hexane derivatives with a step. Based on departure from the active methylene compounds, prepared by functionalization of the preparatory work for the basis of cyclopropane , this paper is intended to develop simple methods to build 3 - oxa-bicyclo [3.1.0] hexane derivatives as the goal, to perfect a Cyclopropane synthesis, and five-membered ring derivatives strategy commonly.3 - oxa-bicyclo [3.1.0] hexane compounds have important biological activity of the basic structural units of natural products, but also a number of important basic framework of pharmaceutical active compounds. 3 - oxa-bicyclo [3.1.0] hexane derivatives research is one of the hot of organic synthetic chemistry research. Typically, the synthesis of 3 - oxa-bicyclo [3.1.0] hexane derivatives, the main methods include: Allyl Diazo compounds combined intramolecular reaction of dibromo-cyclopropane-metal carbene insertion reaction, enyne in the under the action of transition metal ring and the free radical cyclization reaction of cyclopropane compounds oxidation, hydrolysis and so on. However, the limitations of existing methods exist, such as higher raw material, the expensive reagents or catalysts, harsh reaction conditions and so on.This paper intends to base on the work front, from the molecular design proceeding from the easily avalible vinyl cyclopropane compounds and small organic molecules NBS, through the choice of reaction conditions to optimize the new strategy of synthetic 3 oxa-bicyclo [3.1.0] hexane derivatives.