423. Experiments towards the synthesis of corrins. Part II. The preparation and reactions of Δ¹-pyrroline 1-oxides

Abstract

The reduction of y-nitro-carbonyl compounds to give A'-pyrroline l-oxides is described and the reactions of several such N-oxides are reported. THE corrin nucleus, parent of the macrocyclic component of the vitamin B,, molecule, is at an oxidation level between that of the pyrroles and the Al-pyrrolines and, in our synthetical studies in this field, it became apparent that the Af-pyrroline l-oxides might offer a flexibility in synthesis somewhat greater than the parent Schiff bases.The A1-pyrroline l-oxides (I) are cyclic nitrones derivable by oxidation of hydroxylamines (11) or by cyclisation of a y-hydroxyamino-carbonyl compound (111). As R4 R4 R4 R4 . ; I J -J R S = ;:rJ +/ RS -;rio.R5 -.;I!O.R

Baicalein attenuates oxidant stress in cardiomyocytes

“…The spin trap 5-methoxycarbonyl-5-methyl-1-pyrroline-N-oxide (MMPO) was synthesized on the basis of methods described previously (5,33). The structure of baicalein and the reaction of MMPO with O 2 Ϫ ⅐ are shown in Fig.…”

Synthesis of 3,4-dihydro-2H-pyrrole 1-oxide based aldonitrones as potential spin trapping agents

“…9,10 Starting 2b, containing naphthalene-1-yl group as fluorescent moiety and ester group for further transformation into hydrophilic carboxyl group could be synthesized by reaction of ethyl 2-bromo-2-(naphthalene-1-yl)acetate with sodium nitrite in DMF in the presence of phloroglucinol similarly to that, described for ethyl 2-bromophenylacetate. 11 However in the case of 1 the main, if not the sole product of the reaction was ethyl 2-hydroxy-2-(naphthalene-1-yl)acetate 2a, probably due to significant steric hindrance (Scheme 2).…”

Synthesis and spin trapping kinetics of new alkyl substituted cyclic nitrones

“…Synthesis involved essentially the conversion of secondary aliphatic nitroalkanes to nitrones via a procedure developed by Todd and co-workers (13). Several variations in experimental conditions for these reactions were required.…”