The preparation of the crystalline amide 2 is reported. Conjugate addition to 2 proceeded with the expected high diastereocontrol to give 3. This set the stage for subsequent intramolecular alkylidene C-H insertion to give, after ozonolysis and aldol condensation, (-)-mesembrine 1. Amide 2 should be a useful chiron for the enantioselective construction of cyclic quaternary centers.

Saponarin, apigenin 6-C- and 7-O-bis-β-D-glucoside, was synthesized in an overall yield of 37% via 11 steps, which included the C-glycosylation of 2,4-O-dibenzylphloroacetophenone, the introduction of a cinnamoyl residue by aldol condensation, the formation of a flavone by regioselective deprotection, and oxidative ring-closure to the final regioselective deprotection and stereoselective O-glyc...

The title compound, C(14)H(11)ClO(2), was prepared from 4-chloro-hypnone and 5-methyl-furfural by an aldol condensation reaction. The dihedral angle formed between the two benzene rings is 7.71 (2)°. The crystal structure is stabilized by C-H⋯O inter-actions.

A general synthetic approach to the isoprostanes has been established, based on intermolecular aldol condensation of a diazo ketone with an unsaturated aldehyde, followed by cyclization of the resulting diazo ketone to the cyclopropane. Subsequent kinetic opening with thiophenol followed by further elaboration then leads to the isoprostane. The history of this approach and the details of its de...

Treatment of the diol 6 with KH and 18-C-6 at room temperature gives the cyclopentenone 7 in good yields. Mechanistic analysis reveals that this is the first case of an anionic oxy retro-ene reaction followed by a tandem intramolecular aldol condensation. Reaction: see text.

A core 4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridine-4-one scaffold is elaborated at C-3(Me) by base-mediated aldol condensation to give new 3-alkenyl-4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridine-4-ones, which are masked forms related to the acylpyridone natural products.

A highly diastereoselective tandem ring-enlargement and aldol condensation process involving multicomponent reactions of ethereal tricyclooxonium ylide intermediate with alcohols, mono- or dialdehydes in the presence of titanium(iv) isopropoxide is described to furnish alkoxyoctahydro-1,4-benzodioxocin-6(5H)-one ring systems.

Yolk-shell TiO2 microspheres were synthesized via a one-pot template-free solvothermal method building on the aldol condensation reaction of acetylacetone. This unique structure shows superior light scattering ability resulting in power conversion efficiency as high as 11%. This work provided a new synthesis system for TiO2 microspheres from solid to hollow and a novel material platform for hig...

N-Nitrosobis(2-oxopropyl)amine, a potent carcinogen for the pancreas in Syrian hamsters, undergoes a facile, base-catalyzed, intramolecular aldol condensation to yield N-nitroso-5-hydroxy-5-methyl-3-piperidone. This cyclic nitrosamine then decomposes to yield 3-hydroxy-5-methylpyridine.

The aldol condensation of model compounds furfural and acetone on the selected base catalysts have been performed. The activity of MgO was compared with industrially produced hydrotalcite and the series laboratory prepared hydrotalcites. Si×MAl2O4 hydrotalcites (M = Mg, Zn, Ni, Co, Cu, and Fe) were prepared by the solgel method at low calcination temperature of 300°C. The properties of the cata...