Swern Oxidation of Bicyclo[2.2.1]hept-5-ene-2,3-diol and Its Pyrazine-fused Derivatives: An Improved Synthesis of Bicyclo[2.2.1]hept-5-ene-2,3-dione and An Unexpected Ring-Opening Reaction

Abstract

An improved synthesis of bicyclo[2.2.1]hept-5-ene-2,3-dione by Swern oxidation of bicyclo[2.2.1]hept-5-ene-2,3-diol, and an unexpected ring-opening reaction by the Swern oxidation of pyrazine-fused congeners are described.

Cyclovoltammetric Investigation into the Homoconjugation of Plural Pyrazine Rings Linked by Bicyclo[2.2.2]octadiene Spacers

“…However, our previous attempts to synthesize the diketone 8, which seems a promising intermediate for the synthesis of 5, had been unsuccessful because the Swern oxidation of the exo-cis diol 7, prepared from 6, had resulted in an unexpected ring-opening reaction. [16] The results motivated us to prepare the dipyrazine-fused derivatives 2Ϫ4, linked by the bicyclo[2.2.2]-octadiene skeleton, as target molecules with which to invest- igate homoconjugation between two electron-deficient pyrazine rings, and we wish to describe their synthesis and redox properties here. We also report the synthesis and properties of the bridged polyazapolyacenes 25Ϫ27, which had been expected to constitute a novel multi-step redox system.…”

α‐Diimine–Palladium Complexes Incorporated in Vinylic‐Addition Polynorbornenes: Synthesis and Catalytic Activity

“…Norbornene derivatives 1 – 4 were synthesized as shown in Scheme . No examples of norbornene‐bearing diimines can be found in the literature, and we followed the method reported by Kobayashi et al for the synthesis of 3 . The first step is a Diels–Alder reaction of cyclopentadiene and vinylene carbonate, which gives 1 in high yield, as a mixture of isomers ( endo/exo = 97:3).…”

“…The reagents used in the synthesis of the monomers and catalytic reactions were purchased from Aldrich, Alfa‐Aesar, and Acros. [Ni(C 6 F 5 ) 2 (SbPh 3 ) 2 ], [PdMeCl(COD)], [Pd(CF 3 CO 2 ) 2 ] and NB(C=O) 2 ( 3 ) were prepared according to literature procedures. Compounds 1 and 2 were prepared with slight modifications of the procedure described by Newman et at ,…”

Synthesis of Novel Purinyl-1'-homocarbanucleosides Based on a Cyclopenta[b]pyrazine System

“…14) Hydroxylation with OsO 4 and methylmorpholine N-oxide 15) in acetone/water afforded a 74% yield of glycol 4, which upon treatment with dimethoxypropane gave acetonide 5. An attempt to convert 5 into diamine 7 in one step by heating with KOH in methanol at 155°C afforded a complex mixture including only traces of the desired product, while a two-steps process, heating of compound 5 with KOH in methanol at 65°C, isolation of the resulting imidazolone 6, and heating of 6 with KOH in methanol at 155°C in a sealed tube, 16) afforded a good yield of a product that could be by identified as 7 by 1 H-NMR spectroscopy.…”