Rearrangement of 1-(1-Alkynyl)cyclopropanols to 2-Cyclopentenones via Their Hexacarbonyldicobalt Complexes. A New Use of Alkyne−Co<sub>2</sub>(CO)<sub>6</sub> Complexes in Organic Synthesis
protective group of the substrates. This rearrangement was successfully applied to cyclopentenone annulation reactions onto cycloalkenes. An efficient synthesis of alkynyl-substituted bicyclo[n.1.0]alkanol derivativesfrom the corresponding cycloalkenes according to Danheiser's protocol was developed, and bicyclic cyclopentenones were obtained in moderate to good yield by applying to these the cobalt-mediated
1-(1-炔基) 环丙醇向 2-环戊烯-1-酮的新重排是在其炔基部分与八羰基二钴 (Co2(CO8)) 络合后进行的。1-(1-炔基) 环丙醇在其炔烃末端具有广泛的取代基,以良好的产率重排为相应的 3-取代的 2-环戊烯-1-酮。In case of the reactions of 1-alkynylcyclopropanols with an alkyl substituent on the cyclopropane ring, either 4-substituted or 5-substituted 2-cyclopenten-1-ones could be selectively obtained by appropriate choice of stereochemistry and protective group of the substrates. 这种重排成功地应用于环戊烯酮环化成环烯烃的反应。根据
Stereoselective sonochemical reductive silylation of geminal dibromocyclopropanes by bulk magnesium
作者:Jonathan Touster、Albert J. Fry
DOI:10.1016/s0040-4039(97)01453-6
日期:1997.9
trimethysilyl chloride and a bicyclic 1,1-dibromocyclopropane in the presence of bulk magnesium affords 1-trimethylsilyl-1-bromocyclopropanes in 72–93% yield. The sonochemical reactions proceed stereoselectively to afford as the major product the product in which the trimethylsilyl group is cis to the hydrogen atoms at the ring juncture.