An acid labile branched PDMAEMA/acetal copolymer with amino group was synthesized by the DE-ATRP and followed by Michael addition. The degradation of the polymer was strongly pH-dependent. High nucleic acid transfection efficiency with low cytotoxicity was observed compared to its non-degradable copolymer counterpart.

We report a highly efficient approach to constructing chiral N,S-acetals using 5-substituted rhodanines as sulfur-bound pronucleophiles catalyzed by natural cinchona alkaloids quinine or quinidine. This α-amination reaction has a broad substrate scope, and the products featuring both rhodanine and N,S-acetal structural motifs were obtained in high yields and excellent enantioselectivities.

We report the first synthesis of a photodegradable hyperbranched polyacetal, wherein every repeat unit carries a photo-labile 2-nitrobenzyloxy moiety. The pristine HBP serves as a positive photoresist to create micron-size patterns; furthermore, by changing the terminal groups to dipropargyl acetal, clickable photo-patterned substrates can be generated.

The reactivity of 2-acylaminoacrylates with ketene diethyl acetal can be modulated by means of thermal conditions to yield cyclobutanes for the preparation of protected beta-hydroxycyclobutane-alpha-amino acids, or catalytic conditions that yield cyclohexanes by tandem condensations to obtain interesting building blocks that are alternatives to Danishefsky's diene.

Carbonylation gets a phase lift: The usual liquid-phase, high-pressure processes for carbonylating formaldehydes are avoided in a novel vapor-phase reaction. Using an acid zeolite (Faujasite) at near-atmospheric pressure dimethoxymethane (DMM; the dimethyl acetal of formaldehyde; see scheme) is carbonylated to produce methyl methoxyacetate (MMAc). This approach provides a new route to ethylene ...

An efficient and highly diastereoselective method for the construction of the hydroxylated tropane skeleton is described. The method features a new intramolecular reductive coupling reaction of N-acyl N,O-acetal with aldehyde, cooperatively mediated by BF(3)·OEt(2) and SmI(2). On the basis of this method, a new enantioselective total synthesis of (-)-Bao Gong Teng A has been accomplished.

The bis-THF cores of annonaceous acetogenins were synthesized using (3R,4R)-1,5-hexadiene-3,4-diol (1) as the sole source of carbon atoms. The methylene acetal function was applied as a new linker/tether to facilitate the ring-closing metathesis.

The first enantioselective synthesis of the fungal metabolite (+)-O-methylasparvenone was achieved in eight steps and 22% overall yield from inexpensive 3,4,5-trimethoxybenzaldehyde dimethyl acetal. Key steps include (i) early-stage asymmetric alkynylation of an aromatic aldehyde with a propiolate, (ii) intramolecular Friedel-Crafts acylation, and (iii) site-selective cleavage of an aryl methyl...

Due to numerous reasons, marine-obtained resources have attracted the interest of researchers. One of the subjects attracted the interest of researchers in recent years in the field of biologist marine algae due to their nutritional value, their benefits for health and their biological activities. In this study, the powder was extracted using acetone, then the extract purified by silica gel col...

Regioselective synthesis of highly functionalized pyranopyrazoles was achieved in excellent yield from phenyl pyrazolone, substituted aromatic aldehyde with nitroketene-N,S-acetal in the presence of indium trichloride as a versatile catalyst under reflux condition in ethanol-water mixture. All reactions preceeded within a short period of time with excellent purity. All of the synthesized compou...