The FLP species 1-BR2-2-NMe2-C6H4 (R = 2,4,6-Me3C6H2, 2,4,5-Me3C6H2) reacts with H2 in sequential hydrogen activation and protodeborylation reactions to give (1-BH2-2-NMe2-C6H4)2. While reacts with H2/CO2 to give formyl, acetal and methoxy-derivatives, reacts with H2/CO2 to give C6H4(NMe2)(B(2,4,5-Me3C6H2)O)2CH2. The mechanism of CO2 reduction is considered.

Laminaribiose, which is the simplest -(1,3)-glucan, is one of the most powerful agents able to increase germination. Its chemical synthesis was revised in detail starting from peracylated donors and easily available glucofuranose protected by acetal groups in the presence of appropriated catalyst and/or promoter. We particularly focused our attention on the nature of the Lewis acid generally re...

A novel class of pH-sensitive PEG lipids bearing acid-cleavable acetal linkages and short PEG chains have been synthesised and used in ternary vector formulations. The cleavage pH was influenced by structural components including the terminal PEG moiety and spacer length.

The title compound, C(14)H(14)O(2), crystallizes in the chiral monoclinic space group P2(1). This acetal is composed of a planar naphthalene ring with a 1,3-dioxane ring substituent, which has a chair conformation. In the crystal structure, symmetry-related mol-ecules are connected via a weak C-H⋯O inter-action to form a helical chain propagating in [010]. While there are no π-π stacking inter-...

The enantioselective vinylogous Michael reaction of vinylketene silyl N,O-acetals derived from α,β-unsaturated N-acyl pyrroles and a broad range of α,β-unsaturated aldehydes proceeds with good regio-, diastereo-, and enantioselectivity when the Hayashi-Jørgensen diphenylprolinolsilylether was employed as a chiral organocatalyst. Products were obtained in generally good yields and as single ster...

CuCl2-mediated intramolecular C-H/C-H cross-dehydrogenative coupling (CDC) of thioalkyl-substituted α-acetyl or α-aroyl ketene N,S-acetals afforded 2-thioalkyl indoles. Tunable C-S bond transformations of the resultant indoles led to highly functionalized N-heterocyclic compounds. A β-thioalkyl is necessary to activate the N,S-acetal substrate and enable the CDC reaction to occur, and the relev...

13C-NMR studies have confirmed the structures of (8S)-8-hydroxyerythromycins A- and B-6,9;9,11-acetal proposed by KROWICKI and ZAMOJSKI2,3) for the products of the m-chloroperbenzoic acid oxidation of 8,9-anhydroerythromycins A- and B-6,9-hemiacetal. The preparations of (8S)-8-methylthiomethoxy- and (8S)-8-methoxyerythromycin B-6,9;9,11-acetals are described. The latter are stable in aqueous ac...

Based on a preactivation protocol with (p-Tol)2SO/Tf2O, a practical, straightforward, and high-yielding synthesis of α-sialyl C-glycosides was accomplished by coupling N-acetyl-5-N,4-O-oxazolidione protected thiosialoside with various trimethylsilyl enol ethers and allyltrimethylsilanes. High yields and excellent α-selectivities were obtained for the strong π-nucleophiles with large nucleophili...