Chemistry of α-nitroepoxides : Synthesis of useful intermediates via nucleophilic ring opening of α-nitroepoxides
作者:Yashwant D. Vankar、Kavita Shah、Anita Bawa、Surendra P. Singh
DOI:10.1016/s0040-4020(01)81002-4
日期:1991.10
Various α-nitroepoxides are converted into corresponding 1,2-diketones via two different ways of ring opening viz. with Pd(O) and with DMSO/BF3·Et2O(or ClSiMe3). In addition to this, a variety of nucleophiles are reacted with α-nitrocyclopentene oxide 6 and α-nitro-cyclohexene oxide 7 to form the corresponding α-substituted ketones which are useful intermediates in organic synthesis. Two of the products
The synthesis and chemistry of azolenines. Part 18. Preparation of 3-ethoxycarbonyl-3-pyrroles the paal-knorr reaction, and sigmatropic rearrangements involving competitive ester migrations to c-2, c-4 and n.
作者:Chiu Pak-Kan、Sannes Michael P.
DOI:10.1016/s0040-4020(01)81514-3
日期:1990.1
N-esters (13) of 1H-pyrroles via competitive [1,5]sigmatropic rearrangements. Isolable intermediate 2H-pyrrole-2-carboxylic esters (l2) are converted similarly into the same products, under the same conditions. Detection of 3H-pyrroles (4) as intermediates in the latter reaction demonstrates for the first time the reversibility of the thermal 2H-pyrrole to 3H-pyrrole interconversion.