Facile Synthesis of Naphthoquinone Spiroketals by Diastereoselective Oxidative [3 + 2] Cycloaddition

Tandem Michael addition/intramolecular isocyanide [3 + 2] cycloaddition: highly diastereoselective one pot synthesis of fused oxazolines.

A base-catalyzed tandem Michael addition/intramolecular isocyanide [3 + 2] cycloaddition of ethyl isocyanoacetate and Michael acceptors with tethered carbonyl groups is described. This reaction leads to the formation of fused oxazolines in a highly diastereoselective manner under very mild conditions.

synthesis of some new sugar based 3, 3-disubstituted monocyclic β-lactams by asymmetric [2+2] cycloaddition reactions

synthesis of some new monocyclic β-lactams containing a quaternary carbon center via a [2+2]cycloaddition reaction is described. the reaction of achiral diphenyl ketene with chiral aldimines derivedfrom chiral 2, 3, 4, 6-tetra-o-acetyl-β-d-galactopyranosylamine, 2, 3, 4, 6-tetra-o-acetyl-β-dglucopyranosylamine and different benzaldehydes resulted in the formation of β-lactams as singlediastereo...

A regio- and diastereoselective platinum-catalyzed tandem [2+1]/[3+2] cycloaddition sequence.

Ni(ClO4)(2)-catalysed regio- and diastereoselective [3+2] cycloaddition of indoles and aryl oxiranyl-dicarboxylates/diketones: a facile access to furo[3,4-b]indoles.

Ni(ClO(4))(2)·6H(2)O-catalysed regioselective and diastereoselective [3+2]-annulations of aryl oxiranyl-dicarboxylates and indoles via selective C-C bond cleavage of oxirane were revealed. The cycloadditions proceed smoothly with high regio- and diastereoselectivity under mild conditions leading to 1H-furo[3,4-b]indoles in good to excellent yields.

Inhibition of synthesis of pyrimidine nucleotides by 2-hydroxy-3-(3,3-dichloroallyl)-1,4-naphthoquinone.

Dichboroablyblawsone [2-hydroxy-3-(3,3-dichboroallyb)-1 ,4naphthoquinone, NSC 126771 ] is of interest as an antiturnor agent. Like certain other naphthoquinones, it is known to be a respiratory poison as a result of interference with electron transport, but it has not been shown that this action is respon sible for its toxicity or antitiumor activity. Studies in cultured Li 210 cells showed tha...