Reactions of carbonyl compounds with α,β-unsaturated nitriles as a convenient pathway to carbo- and heterocycles

Abstract

Abstrad.We re-examine the so-called Nambu-Iona-Lasinio mechanism suggested by Song, Xu and Chin in breaking the supersymmetry in the Wess-Zumino model and show that this mechanism cannot be justified without assuming special effects behveen fermions. The fermion condensation suggested by them corresponds to an mstable vacumm configuration and as a result there is no fermion condensation and no supersymmetg breaking in the model they discuss.

Utilities of Some Carbon Nucleophiles in Heterocyclic Synthesis

“…Two recent reports on this subject are coincident with that proposal [257,258]. The conversion of the latter into substituted tetrahydropyridines and hexahydroquinolines [261][262][263][264] has been studied, but a number of questions remain open with respect to their structure and the direction of cyclization and alkylation [265]. Recently, the reaction of structural analogs-dimedone 240 and Meldrum's acid 461-with arylmethylenecyanothioacetamides, or aromatic aldehydes and cyanothioacetamide in the presence of secondary and tertiary amines, which produces the corresponding adducts of Michael addition has been described.…”

“…It is known that reactions of compounds like 465 withbromoketones in DMF is accompanied by loss of Meldrum's acid and leads to the formation of substituted 2-thiazolylcyanoethylenes [265]. The results of interaction of Michael adducts with other alkyl halides have not been described.…”

Use of cyclic aliphatic ketones for spiro 2-amino-3-cyano pyrano[3,2-c]chromene formation

“…The resulting Michael adduct 11 then undergoes intramolecular cyclization producing the annelated iminopyran 12. Subsequent tautomeric [1,3]sigmatropic shift gives compound 8 (Scheme 1).…”

“…However, the proposed mechanism is supported to some degree by isolation of analogous Michael adducts in the previously studied reaction of 4-hydroxycoumarin with arylidenecyanoacetamides. 3 On the other hand the three component reaction system of 4-hydroxycoumarin 1a, malononitrile 7 and substituted acetophenones 13(a-c) as the carbonyl compound under analogous conditions failed to produce any chromenes 15(a-c). It was found that the acetophenones 13(a-c) did react with malononitrile 7 to give unsaturated nitriles 14(a-c) but these did not undergo Michael reaction with the coumarin anion.…”

Cross reactions of cyanoacetic acid derivatives with carbonyl compounds 3. One-step synthesis of substituted 2-amino-5-oxo-4,5-dihydropyrano[3,2-c]chromenes

“…However, this scheme is confirmed to some degree by isolation of analogous Michael adducts (Z = CSNH 2 ) in the previ ously studied reactions of 4 hydroxycoumarin with aryl idenecyanothioacetamides. 4 The three component reaction between coumarin 1, malononitrile 7a, and 1 benzyloxycarbonylpiperidin 4 one (13) as the carbonyl compound follows a different pathway. Under analogous conditions (see above), malo nonitrile 7a reacts with piperidin 4 one 13 to give unsat urated nitrile 14, which dimerizes into spiroheterocycle 15 rather than reacting with coumarin 1.…”