Preparation of Cyclic Sulfites by Transesterification of Diols and Diisopropyl Sulfite
作者:Steven A. King、Brenda Pipik、David A. Conlon、M. Bhupathy
DOI:10.1080/00397919708003344
日期:1997.2
Abstract CyclicSulfites of 1,2-, 1,3- and 1,4-diols can be prepared in high yield by acid or base catalyzed transesterification with diisopropyl sulfite.
The Pyrolysis of Sulfites. I. Symmetrical Sulfites
作者:Charles C. Price、Giancarlo Berti
DOI:10.1021/ja01634a001
日期:1954.3
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.
Induction of Cholesteric Mesophases by Simple Cyclic Derivatives of <i>p,p</i><i>‘</i>-Disubstituted 1,2-Diphenylethane-1,2-diols: Importance of Shape and Polarizability Effects
A systematic study of the cholesteric induction in nematic solvents (MBBA and E7) by some cyclic derivatives of unsubstituted and p,p'-disubstituted-1,2-diphenylethane-1, shows that the values of the twisting power are significantly dependent on the nature of the link connecting the two oxygen atoms and on the nature of the p,p'-substituents. This result has been interpreted considering that the nature of the bridge affects the overall molecular shape and the p,p'-substituents affect both the molecular polarizability and shape. This investigation points out that the polarizability of the solute and the solvent is the main parameter in determining the value of the twisting power while electrostatic arene-arene interactions contribute to a less extent. It has been also observed that solutes having the same structure and the same absolute configuration can induce cholesteric helix of opposite sign depending on the substituent on the aromatic ring. This finding indicates that configurational assignments by cholesteric induction are reliable only if high values of twisting power are measured.