Ring opening of epoxides with NaHSO4: isolation of β-hydroxy sulfate esters and an effective synthesis for trans-diols
摘要:
Sodium hydrogen sulfate (NaHSO4) was observed to be highly effective as a reagent or catalyst in the ring-opening reactions of epoxides under mild conditions. Reaction of epoxides with NaHSO4 gave isolable P-hydroxy sulfate esters and vicinal diols. Experimenting with different epoxides, the study investigated the scope of the ring-opening reaction. (C) 2008 Elsevier Ltd. All rights reserved.
A new metal-free protocol is described for the synthesis of terminal acetals by tandem oxidative rearrangement of olefins using oxone as an oxidant in the presence of iodine. Moreover, a one-pot procedure for the preparation of glycol mono esters from olefins is also presented for the first time using the same reagent system.
An unexpected 1,2-hydride shift in phosphoric acid-promoted cyclodimerization of styrene oxides under solvent-free conditions. A synthetic route towards 2,4-disubstituted 1,3-dioxolanes
作者:Ofentse Mazimba、Runner R. Majinda、Ishmael B. Masesane
DOI:10.1016/j.tetlet.2009.08.044
日期:2009.10
A 1,2-hydride shift in the phosphoric acid-promoted cyclodimerization of styrene oxide and its chloro derivatives under solvent-free conditions leading to 2,4-disubstituted 1,3-dioxolanes is described. Methoxy substituents on the aromatic ring of the styrene oxide prevent the 1,2-hydride shift reaction leading to substituted 1,4-dioxanes. A possible mechanism for the formation of the 1,3-dioxolanes
Lewis-Acid-Catalysed Tandem Meinwald Rearrangement/Intermolecular [3+2]-Cycloaddition of Epoxides with Donor-Acceptor Cyclopropanes: Synthesis of Functionalized Tetrahydrofurans
作者:Ashok Kumar Pandey、Asit Ghosh、Prabal Banerjee
DOI:10.1002/ejoc.201403590
日期:2015.4
A Lewis-acid-catalysedtandemMeinwaldrearrangement/[3+2]-cycloaddition of epoxides with donor–acceptorcyclopropanes to synthesize varieties of cis-2,5-aryl-benzyl-substituted tetrahydrofurans is described. An enantioselective version of the same transformation was achieved using an InCl3–PyBOX catalyst system.