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The manuscript describes a synthetic route for the formation of 5‐(methylisoindole‐1,3‐dione) pyrimidinones by [4+2] cycloaddition reactions of functionalized 1,3‐diazabuta‐1,3‐dienes with 2‐(3‐Oxo‐allyl)‐isoindole‐1,3‐dione generated in situ from phthaloylalanine and tosyl chloride using triethylamine as a base. The functionalized 5‐(methylisoindole‐1,3‐dione) pyrimidinones were further explored in the deprotection of amines to afford a variety of 5‐methylamino pyrimidinones. The synthesis of such functionalized pyrimidinones is significant as they have a wide range of pharmacological profiles and are valuable as organic synthons. Mechanistic insights are also proposed for the given synthetic methodology. [ABSTRACT FROM AUTHOR]

The functionalization of β-lactams at C-3 position are useful for the strategic improvement in both the dimensions, namely synthetic utility, as versatile intermediate in organic synthesis and biological potential of these heterocyclic systems. The present manuscript involved the π-facial selective synthesis β-lactam hybrids employing highly regioselective and diastereoselective Oxo-Diels-Alder reaction of diethyl ketomalonate with α-dienyl-β-lactam with stereocentres at its α- and β-positions. This protocol provided the cycloaddition of α- and β-stereocentric diene with symmetrical heterodienophiles forming biologically potent regioselective and diastereoselective α-lactams substituted pyrano bifunctional hybrids in good yields and β-facially selectivity. [ABSTRACT FROM AUTHOR]

3-Butadienyl-β-lactams are useful organic synthon which have efficiently been explored for the synthesis of a variety of heterocyclic systems. The present review compiles the various reports on the synthesis of 3-butadienyl-β-lactams and their explorations in the development of variety of monocyclic as well as condensed heterocyclic systems. [ABSTRACT FROM AUTHOR]

The reactions of butadienylketene with variety of 1,4-diazabuta-1,3-dienes are studied. The reactions resulted in the formation of previously unknown functionalized cis butadienyl-4-iminomethyl-azetidin-2-ones and butenylidene-butadienyl-[2,2′-biazetidine]-4,4′- diones. Butadienyl ketene reacts in fashion with both iminic portion of 1,4- diazabuta-1,3-dienes and competitive [4+2] of 1,4-diazabuta-1,3-dienes as 4π component with butadienyl ketene as 2π component are not observed. [ABSTRACT FROM AUTHOR]

Highly diastereo- and π-facially selective imino Diels–Alder cycloadditions of 3-allylideneamino-2-azetidinones having stereocentres at its α- and β-positions, with symmetrical dienophiles leading to the formation of biologically potent (2-oxo-4-styrylazetidin-3-yl)–pyridine hybrids have been reported. [ABSTRACT FROM AUTHOR]

Abstract: The regioselective nitroso Diels–Alder (NDA) cycloadditions of 3-dienyl-2-azetidinones with nitrosobenzene to generate oxazine-substituted β-lactams in excellent yields are reported. The amidiolytic ring opening of the cycloadducts with sodium methoxide followed by iodocyclization using I2/K2CO3 etiquette to capitulate previously unknown, multisubstituted pyrroloxazine in outstanding yields is also accounted. [Copyright &y& Elsevier]