Access to the 2H-Tetrahydro-4,6-dioxo-1,2-oxazine Ring System from Nitrone via a Tandem Nucleophilic Addition and Transesterification Reaction

Abstract

A general and efficient synthesis of the 2H-tetrahydro-4,6-dioxo-1,2-oxazine ring system through a tandem nucleophilic addition and transesterification reaction is described. The reaction is highly functional-group-tolerant and proceeds under mild conditions, affording the corresponding products in good to excellent yields. This method represents the first general synthetic route to access this heterocyclic scaffold, which exists in the complex natural products alchivemycin A and B with significant antibiotic activities.

β‐Ketoesters: An Overview and It's Applications via Transesterification

“…The synthesis of 2H-tetrahydro-4,6-dioxo-1,2-oxazine ring system through a tandem nucleophilic addition and transesterification reaction has developed by Shaoqiang Yang et al [48] as shown in Scheme 25. The reaction requires mild conditions and observed highly functional-group-tolerance towards the synthesis.…”

“…Iron(III) dimer complex, [31] Modified Vilsmeier-Haack reagents TCCA/DMF, TCTA/DMF (SOCl 2 /DMF, POCl 3 /DMF), [32] FeÀ Mn cyanide, [33] Stefan et. al., reported the boronic acid synthesis via monophasic transesterification by evaporation of reagents/ byproducts, [34] Zn-PAM, [35] MCS, [36] ultrasonic technique, [37] DBU-CO 2 , [38] enzymatic transesterification, [39] M 2 CO 3 or MI (M = Li, Na, K, Cs), [40] pPh-SO 3 H & pBPA-SO 3 H, [41] Ti(Oi-pr) 4 , [42] NaOR, [43] Metal/ ETS-10, [44] BBAIL, [45] EmimOAc, [46] BF 3 .OEt 2 , [47] Zn(Me) 2 , [48] N-Heterocyclic olefins, [49] microwave irradiation, [50] dilithium tetra-tertbutylzincate, [51] K 2 CO 3 /DMSO, [52] Ionic liquid (references therein), [53] methylboronic acid, [54] AuÀ Cu nanoparticles, [55] CO 2 / Novozym-435, [56] CuFe 2 O 4 , [57] Cesium carbonate, [58] Ion-exchange resins (Lewatit K1221), [59] imidazolium ionic liquids, [60] 4-(3methyl-1-imidazolio)-1-butanesulfonic acid triflate, [61] Mn(II) Carbonate & Mn(II)Sulfate, [62] DBU at high pressure, [63] ball-mill technique, [64] AgOTf, [65] Sol-Gel MoO 3 /TiO 2 , [66] lipase from Aspergillus niger, [67] TEA, [68] Sn-catalyst, [69] lanthanum(III) Isopropoxide, [70] Candida rugo...…”

Redox Modifications in the Biosynthesis of Alchivemycin A Enable the Formation of Its Key Pharmacophore

“…4 Because of its potent bioactivity and complicated structure, several studies have investigated the chemical synthesis of 1. 5,6 Moreover, a previous biosynthetic study used 13 C-labeled precursors to show that the carbon backbone of 1 is derived from five methylmalonyl-CoA molecules, nine malonyl-CoA molecules, and one glycine molecule, which are assembled via a polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) hybrid pathway (Figure S1). 7 Through bioinformatics analysis of the draft genome of the S. sp.…”

Oxa–diketopiperazines: Access and Conformational Analysis of Potential Turn Inducers

“…According to the notable success of heterocycles in our pharmacopeia, there is a recent enthusiasm to pursue the development of compounds containing both nitrogen and oxygen as adjacent atoms . In this sense, the biological potential of oxadiazine as antibacterial or pesticide, makes its skeleton relevant for organic chemists and drug designers.…”