Nucleophilic Ring Opening of Cyclic 1,2-Sulfites with Nitrogen Nucleophiles. A Route to Enantiopure Benzylic Amino Alcohols.
作者:Kirsten Nymann、Saravanapavan Mylvaganam、John S. Svendsen、Inamur Rahaman Laskar、Nirmalendu Ray Chaudhuri、Kirsi Ranta、Teófilo Rojo
DOI:10.3891/acta.chem.scand.52-1060
日期:——
The reaction between cyclic 1,2-sulfites and two imide and two sulfonamide nucleophiles has been Investigated in order to develop a procedure for the enantioselective preparation of N-protected vicinal amino alcohols. The results show that both imide and sulfonamide anions react with cyclic sulfites, yielding the desired products. In some cases the regioselectivities are low, and for the sulfonamides products originating from nucleophilic addition to the sulfite sulfur are observed.
Nucleophilic Reactions between Cyclic 1,2-Sulfites and Chloride Ions.
作者:Kirsten Nymann、Linda Jensen、John S. Svendsen、T. Anthonsen、Ryszard Gawinecki、Günter Häfelinger、Muhammed Nour Homsi、Frank K. H. Kuske、Monika Haugg、Nathalie Trabesinger-Rüf、Elmar G. Weinhold
DOI:10.3891/acta.chem.scand.50-0832
日期:——
When cyclic 1,2-sulfites are ring opened by chloride ion, the chlorohydrins are formed with low regio and stereo-selectivity. The mechanisms involved in the process were investigated by measuring the stereochemical outcome of the reactions. The results showed that reversible inversion pathways (S(N)2 reactions) and a retention pathway (S(N)2i reaction) gave rise to the loss in ee in both the chlorohydrins and in the cyclic 1,2-sulfites.
LOHRAY, BRAJ B.;AHUJA, JAIMALA R., J. CHEM. SOC. CHEM. COMMUN.,(1991) N, C. 95-97
Synthesis of homochiral amino alcohols, aziridines and diamines via homochiral cyclic sulphites
作者:Braj B. Lohray、Jaimala R. Ahuja
DOI:10.1039/c39910000095
日期:——
Vicinal diols react with thionyl chloride to give 1,2-cyclic sulphites in quantitative yield, which undergo facile ring opening by lithium azide in dimethylformamide to yield azido alcohols and the latter in turn have been stereoselectively transformed into amino alcohols, aziridines and diamines.