Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate

• Eloi P. Coutant,
• Vincent Hervin,
• Glwadys Gagnot,
• Candice Ford,
• Racha Baatallah and
• Yves L. Janin

Beilstein J. Org. Chem. 2018, 14, 2853–2860, doi:10.3762/bjoc.14.264

• -bromo-α-hydroxyiminocarboxylate and various alkylfuranes. Keywords: α-amino ester; α-hydroxyimino ester; [2 + 4] cycloadditions; [2 + 3] cycloadditions; Knoevenagel; nitrosoacrylate; Suzuki–Miyaura; Introduction Our current work on the chemistry of imidazo[1,2-a]pyrazin-3(7H)-one luciferins [1] has

• -hydroxyimino esters [23][24][25][26] and then extensively used to prepare a wide range of amino acids [3][27]. This proceeds via a [2 + 4] cycloaddition between ethyl nitrosoacrylate, generated in situ from the reaction of sodium carbonate and furan 48, to give the cycloadduct 49. Then, upon heating, a

• explanation for these average yields could be the occurrence upon the base reaction with compound 47 of cis and trans conformations of the nitrosoacrylate. The cis one would be susceptible to undergo an immediate [2 + 4] cycloaddition with the furan whereas the trans form would not, and since the

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

• Yaroslav D. Boyko,
• Valentin S. Dorokhov,
• Alexey Yu. Sukhorukov and
• Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

• . Gilchrist [70] employed oximinoalkylation of pyrrole as the initial stage in the synthesis of 1,2-dihydropyrrolizinone antibiotic 82 [71][72][73] (Scheme 29). The addition of ethyl 2-nitrosoacrylate (generated from ethyl bromopyruvate oxime) to pyrrole under basic conditions afforded product 67a in 61