The transformation of (5R)-2,6-di-O-benzyl-5-C-methoxy-beta-D-galactopyranosyl-(1-->4)-2,3:5,6-di-O-isopropylidene-aldehydo-D-glucose dimethyl acetal (8) into partially protected derivatives of D-xylo- and L-lyxo-aldohexos-5-ulose has been reported, applying appropriate epimerisation methods to its 3'-O- and 4'-O-protected alcoholic derivatives.

Treatment of 1-(5-acetyl-3,4-dimethythieno[2,3-b]thiophene-2yl)ethanone (1) with dimethylformamide dimethyl acetal afforded enaminone derivative 2, which reacted with amino derivatives to give the corresponding bis-pyrimidine, bis-pyrazole, bis-triazolo-pyrimidine and bis-benzoimidazopyrimidine derivatives.

1,2-Disubstituted-3,4-dihydronaphthalenes could be conveniently synthesized with high yields by the cycloaddition reactions of easily available vinylarenes with electron-deficient alkynes such as dimethyl, or diethyl acetylenedicarboxylate, methyl phenylpropiolate in the presence of DMF.DMA (N,N-dimethylformamide dimethyl acetal) as organocatalyst.

Selenocysteine containing peptoids and peptide-peptoid conjugates were synthesized by combinatorial Ugi-MCRs (multicomponent reactions) in water: for the first time, an acetal (selenoacetal 2a) was used in Ugi-MCR to furnish selenocysteine peptoids in one step as model compounds for selenocysteine peptides and proteins.

A new well-behaved dynamic library (DL) based on acetal cyclophanes incorporating diphenylmethane units is described. The effective molarities of the first two members of this library of cyclic oligomers C(2) and C(3) have been obtained from concentration profiles. Amplification of the dimer in the presence of a silver template, and cross-equilibration experiments are also reported.

Five new monoterpene indole alkaloids, naucleamides A-E (1-5), were isolated from the bark and wood of Nauclea latifolia, and the structures and relative stereochemistry were elucidated from the spectroscopic data. Naucleamide E (5) is a unique monoterpene indole alkaloid possessing a pentacyclic ring system with an amino acetal bridge.

Highly enantioselective protonation of α-halo and alkoxy carboxylic acid-derived ketene disilyl acetals is achieved by using P-spiro chiral diaminodioxaphosphonium barfate as a Brønsted acid catalyst, where the enantiofacial discrimination by the catalyst mainly stems from the recognition of the electronic difference between two substituents on the ketene disilyl acetal.

The first total synthesis of (29S,37S)-malevamide E (1), a potent ion channel inhibitor, has been achieved in a convergent fashion involving Julia-Kocienski olefination, Urpi acetal aldol and Shiina macrolactonization reactions as the key steps. The strategy developed herein is amenable for the synthesis of the other possible isomers in search for the correct stereoisomer of the naturally occur...

The selective reduction of CO2 to the formaldehyde level remains an important challenge and to date only a few catalysts have been developed for this reaction. Herein, we report an efficient catalyst that consists of a bis(phosphino)boryl nickel hydride complex in combination with B(C6F5)3, for the highly selective hydrosilation of CO2 to bis(silyl)acetal derivatives.

Orthogonally protected monosaccharide building blocks have been prepared using TCT in a one-pot multicomponent transformation. The process involves successive steps of arylidene acetalation, esterification and regioselective reductive acetal cleavage. High regioselectivity, scope for using a broad range of substrates, functional group tolerance, mild reaction conditions, easy handling process a...