2,6-Anhydro-1,3-di-O-benzyl-d-mannitol

In the title compound, C20H24O5, the six-membered pyran­ose ring adopts a chair conformation. The dihedral angle between the planes of the phenyl groups of the benzyl substituents is 63.1°. Two types of inter­molecular O—H⋯O hydrogen bonds lead to the formation of infinite chains along the b axis. Only weak C—H⋯O contacts exist between neighboring chains

Dimethyl hydrazine-1,2-dicarboxyl­ate–triphenyl­phosphine oxide (1/1)

In the crystal structure of the title compound, C4H8N2O4·C18H15OP, two triphenyl­phosphine oxide mol­ecules and two dimethyl hydrazine-1,2-dicarboxyl­ate mol­ecules are connected via N—H⋯O hydrogen bonds of moderate strength and are related via a twofold rotational axis. Weak Car—H⋯ O contacts strengthen the crystal structure

3-De­oxy-1,2-di-O-isopropyl­idene-5-O-tosyl-d-threo-pentofuran­ose

In the crystal structure of the title compound, C15H20O6S, the two independent mol­ecules crystalllize in a chiral setting with two different conformations, twisted 4 T 3 and envelope 4 E, for the furan­ose rings. Weak C—H⋯O contacts strengthen the crystal structure

3′-O-Acetyl-2′-de­oxy­uridine

In the two independent but very similar mol­ecules of the title compound, C11H14N2O6, both nucleobase fragments are nearly planar (both within 0.01 Å) while the furan­ose rings exhibit 2 E-endo envelope conformations. In the crystal, the two 3′-O-acetyl-2′-de­oxy­uridine mol­ecules form a pseudosymmetric dimer of two bases connected via two nearly identical resonance-assisted N—H⋯O hydrogen bonds. The resulting pair is further connected with neighboring pairs via two similar O—H⋯O bonds involving the only hydroxyl group of the 2′-de­oxy­furan­ose fragment and the remaining carbonyl oxygen of the nucleobase. These inter­actions result in the formation of an infinite ‘double band’ along the b axis that can be considered as a self-assembled analogue of a polynucleotide mol­ecule with non-canonical Watson–Crick base pairs. The infinite chains of 3′-O-acetyl-2′-de­oxy­uridine pairs are additionally held together by C—H⋯O inter­actions involving C atoms of the uracyl base and O atoms of carbonyl groups. Only weak C—H⋯O contacts exist between neighboring chains

Carbohydrate chiral-pool approach to four enantiomerically pure 2-naphthylmethyl 3-hydroxy-2-methylbutanoates

D-Glucose, L-Xylose, and D- and L-arabinose were sources of chirality to obtain four enantiomerically pure 3-hydroxy-2-methylbutanoic acids, which were reacted with 2-naphthyldiazomethane to furnish their fluorescent 2-naphthylmethyl esters. (C) 2008 Elsevier Ltd. All rights reserved.status: publishe

Synthesis of 4-deoxy-4-C-hydroxymethyl-alpha-L-lyxopyranosyl thymine

The synthesis of 1-[4-deoxy-4-C-hydroxymethyl-alpha-L-lyxopyranosy]thymine has been accomplished by two synthetic routes both starting from methyl 2,3-O-isopropylidene-beta-D-ribopyranoside. The first route makes use of a ring opening, ring closure reaction sequence to increase the proportion of the desired L-isomers. The second route utilizes the soft nucleophilic character of malonyl anions and ozonolytic cleavage of enol ether to introduce the branched chain. The newly obtained pyranosyl nucleoside obtains a C-4(1) conformation with an equatorially oriented thymine moiety.status: publishe

Branched-chain nucleosides: Synthesis of 3'-deoxy-3'-C-hydroxymethyl-alpha-L-lyxopyranosyl thymine and 3'-deoxy-3'-C-hydroxymethyl-alpha-L-threofuranosyl thymine

The synthesis of 3'-deoxy-3'-C-hydroxymethyl branched nucleosides with alpha-L-lyxopyranosyl and alpha-L-threofuranosyl sugar moieties is described The synthetic scheme makes use of a furanose --> pyranose conversion and of the formation of both furanose and pyranose nucleosides during Vorbruggen sugar-base condensation reaction starting from tetra-O-acetyl-3-deoxy-3-C-hydroxymethyl-L-lyxo-(1,6)-furanose. The conformation of the target molecules is discussed.status: publishe

1,2;3,4-Di-O-isopropylidene-l-galactose synthesis from its d-enantiomer

Easy procedure was devised to obtain di-O-isopropylidene-l-galactose from di-O-isopropylidene-d-galactose.status: publishe

Simple approach to 1-O-protected (R)- and (S)-glycerols from L- and D-arabinose for glycerol nucleic acids (GNA) monomers research

5-O-Protected (-Tr, -Sitert-BuPh2) D- and L-arabinofuranoses easily available in multigram quantities were converted to (S)- and (R)-1-O-protected glycerols, respectively, via oxidation (NaIO4) and reduction (NaBH4). Sources of chirality in the targets are the C4 atoms in the substrates. This stereospecific procedure permits a very simple access to both enantiomeric 1-O-protected glycerols for GNA monomers work. (C) 2011 Elsevier Ltd. All rights reserved.status: publishe

Synthesis of Phosphonoglycine Backbone Units for the Development of Phosphono Peptide Nucleic Acids

A series of phosphono-modified backbone mimics based on achiral and chiral N-(dihydroxypropyl)glycine units were obtained by sequential addition of phosphonate and nucleobase moieties to suitably protected dihydroxypropylamines. Simple synthetic strategies enabled the preparation of various target derivatives that will be useful as building blocks for the preparation of new synthetic polymers containing a phosphonate internucleotide linkage in place of the standard phosphodiester bond.status: publishe