The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products

• Dong-Xing Tan and
• Fu-She Han

Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164

• co-workers accomplished the first asymmetric total synthesis of (+)-aplysiasecosterol A (6) by employing a desymmetric enantioselective reduction strategy of 1,3-cyclopentanedione derivative as the key transformation [14]. Their synthesis features a highly efficient desymmetric enantioselective

• -cyclopentanedione derivative was adopted as one of the key reactions, which facilitated the construction of the five-membered ring bearing an all-carbon quaternary center as the key chiral building block. Their synthesis began with 1,3-dione 40 (Scheme 2) [31][32], allylation of this substrate with allylic bromide

• 41 afforded the 1,3-cyclopentanedione derivative 42. Next, the baker′s yeast-catalyzed desymmetric enantioselective reduction of 42 gave the α-hydroxyketone 43 in satisfactory yield and excellent stereoselectivity and diastereoselectivity on a decagram scale [33][34]. Functional group modifications

Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

• Soumyaranjan Pati,
• Renata G. Almeida,
• Eufrânio N. da Silva Júnior and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2021, 17, 762–770, doi:10.3762/bjoc.17.66

• benzoyloxymethyltriazole 1j furnished the product 3n in excellent (82%) yield, the performance of another alkyltriazole 1k was less impressive giving the corresponding product 3o only in moderate (52%) yield. The reaction of model triazole 1a with 2-methyl-1,3-cyclopentanedione (2c) also led to the product 3p in moderate

Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

• Yan Sun,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 8–14, doi:10.3762/bjoc.9.2

• scope of this novel reaction is briefly discussed. Keywords: arylamine; cyclopentanedione; isatin; multicomponent reaction; spiro compound; Introduction The spirooxindole is among the most important class of naturally occurring substances, characterized by highly pronounced biological properties, and

Catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to nitroalkenes by a grinding method

• Zong-Bo Xie,
• Na Wang,
• Ming-Yu Wu,
• Ting He,
• Zhang-Gao Le and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2012, 8, 534–538, doi:10.3762/bjoc.8.61

• [22], a transition-metal-free process for the synthesis of substituted dihydrofurans [23] and a catalyst-free tandem reaction for the synthesis of 5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones in aqueous medium [24]. Recently, when carrying out the reaction of β-nitrostyrene with 1,3-cyclopentanedione under

• . Results and Discussion In our initial study, equimolar amounts of β-nitrostyrene (1a) and 1,3-cyclopentanedione (2a), as a model reaction (Table 1, entry 1), were mixed and ground in a mortar at room temperature. The mixture became sticky and adhered to the wall of the mortar firmly after a few seconds

• solvents gave much lower yields. In fact, there are few reports on the Michael addition of β-nitrostyrene and 1,3-cyclopentanedione. Hrnčiar and Čulák performed the same reaction in methanol using sodium methylate as a catalyst; however, only 85% of product 3a was obtained, and a longer reaction time was