The synthesis of ester and ketone analogues of 1-deoxynojirimycin and castanospermine
1-Amino-1-deoxy-D-glucitol (3) was converted into the 3,4;5,6-di-O-isopropylidene protected ammonium salt 17 which was transformed further into the trans-fused piperidine acetonides 4-8 in six steps and 23-32% overall yield. In the final step, ring closur
Experiments Directed Towards the Synthesis of Anthracyclinones. XIX. Elaboration of 2-Formylquinizarin Through a Wittig Reaction
Reaction of 2-formylquinizarin dimethyl ether (3) with the dimethoxy ylide (6) gives an α,β-unsaturated ester (8) which on hydrogenation, reduction and methylation gives the tetramethoxyanthracene diester (18).When linked to work by Doetz and Popall this
Boniface, Peter J.,Cambie, Richard C.,Carroll, David R.,Marsh, Nicholas F.,Milbank, Jared B. J.,et al.
p. 441 - 450
(2007/10/02)
COPPER(II) IN ORGANIC SYNTHESIS. V. INFLUENCE OF THE NATURE OF COPPER(II) COMPLEXES OF 3-ARALAMINOMETHYLENEOXINDOLES ON THEIR REACTIVITY WITH DIMETHYL ACETYLENEDICARBOXYLATE
3-Arylaminomethyleneoxindoles 1a-f gave different copper(II) complexes according to the type of oxindole N-substitution.Tetra-μ-acetatobiscopper(II) complexes 2e-f underwent oxidative fragmentation and no significant product was isolated when they were treated with dimethyl acetylenedicarboxylate (DMAD).Biscopper(II) complexes 2a-d reacted with DMAD and Michael adducts 3a,d formed.Only two adducts (3b,d) were stable at room temperature and decomposed under refluxing dioxan; 3a,c were not stable enough to be isolated.All gave dimethyl 2-(3-oxindolidene)succinates 4a,c whose structures were confirmed by an independent synthesis.The relationship between the structure of the copper(II) complexes and their reactivity is discussed.