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Shai Sarussi 《代数通讯》2017,45(1):411-419
Let T be a totally ordered set and let D(T) denotes the set of all cuts of T. We prove the existence of a discrete valuation domain Ov such that T is order isomorphic to two special subsets of Spec(Ov). We prove that if A is a ring (not necessarily commutative), whose prime spectrum is totally ordered and satisfies (K2), then there exists a totally ordered set U?Spec(A) such that the prime spectrum of A is order isomorphic to D(U). We also present equivalent conditions for a totally ordered set to be a Dedekind totally ordered set. At the end, we present an algebraic geometry point of view.  相似文献   
2.
One of the more important transformations in aromatic chemistry involves nitration of the ring followed by reduction1 of the nitro group to the corresponding primary amine. Despite its low cost, ease of handling, and known2 property of being a convenient hydrogen donor, formic acid (or formate salts, which are even more active hydride donors2) was not utilized for this reduction until recently when Heck and Cortese reported 3 the palladium-catalyzed reduction of nitroaromatics using triethylammonium formate. Since the latter reagent in N,N-dimethylformamide (DMF) had previously4 been shown to reduce the carbon-carbon double bond in good Michael acceptors without the presence of a metal catalyst, we decided to examine non-catalytic systems involving formic acid5 for effecting reduction of the nitro group.  相似文献   
3.
We advance the use of reactive doped sol-gel materials as heterogeneous reagents for organic-chemistry synthesis. Three approaches were demonstrated with SiO2-based materials: Direct physical entrapment of the organic reagent; in-situ generation of an inorganic reagent within the matrix; and covalent attachment of the reagent to the matrix. With the first, entrapped p-toluenesulfonic acid facilitated the 100% yield esterification of benzoic acid with 1-pentanol, and the 100% dehydration of 1-tetralol to 1,2-dihydronaphthalene; with the second approach, a sol-gel oxidant, SiO2/MnO2 was used to convert benzyl alcohol to benzaldehyde and 1-tetralol to 1-tetralone; and with the third, anchored propylamine facilitated dehydrobromination reactions resulting in double-bond formation. Several other reactions with these reagents are described, and their reactivities analyzed.  相似文献   
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