Novel neutral glycosphingolipids isolated from the plerocercoids of a tapeworm, Spirometra erinacei, may be expected to be involved in host-parasite interactions. We have synthesized this glycosphingolipid analogue containing 2-branched fatty alkyl residue in place of ceramide. Glycosylation of nonreducing-end trisaccharide derivative 15 with the reducing-end disaccharide derivative 17 in the p...

Two new molecular structures, namely 1,3-bis(trimethylsilyl)-1H-benzimidazole-2(3H)-thione, C13H22N2SSi2, (2), and 1-trimethylsilyl-1H-benzimidazole-2(3H)-thione, C10H14N2SSi, (3), are reported. Both systems were derived from 1H-benzimidazole-2(3H)-thione. Noncovalent C-H···π interactions between the centroid of the benzmidazole system and the SiMe3 groups form helicoidal arrangements in (2). D...

Thienopyrimidine-based bisphosphonates were identified as a new class of nitrogen-containing bisphosphonate (N-BP) inhibitors of the human farnesyl pyrophosphate synthase (hFPPS). Analogs were prepared via cyclization of 2-(1-(trimethylsilyl)ethylidene)malononitrile to 2-amino-4-(trimethylsilyl)thiophene-3-carbonitrile in the presence of elemental sulfur. Direct ipso-iododesilylation of this in...

The preparation of triethylphosphine adducts of cyclic disilylated or digermylated germylenes was achieved by reaction of 1,4-dipotassio-1,1,4,4-tetrakis(trimethylsilyl)tetramethyltetrasilane with GeBr2·(dioxane) and PEt3. Phosphine abstraction with B(C6F5)3 allowed formation of the base-free germylenes, which undergo 1,2-trimethylsilyl shifts to the germylene atom to form the respective silage...

We describe the first synthesis of homoallyl ethers from acetals and allyltrimethylsilane using microwave heating and CuBr as a promoter. This method works best for aromatic acetals, giving the corresponding homoallyl ethers in good to quantitative yield.

Crown ethers are small, cyclic polyethers that have found wide-spread use in phase-transfer catalysis and, to a certain degree, in protein chemistry. Crown ethers readily bind metallic and organic cations, including positively charged amino acid side chains. We elucidated the crystal structures of several protein-crown ether co-crystals grown in the presence of 18-crown-6. We then employed biop...

Novel 4-acyl-5-pyrazolones having aza-15-crown-5 (HPMP-A15C5) and aza-18-crown-6 (HPMP-A18C6) moieties as an intramolecular synergist have been synthesized by simple coupling reactions between 1-phenyl-3-methyl-4-chloroacetyl-5-pyrazolone and the corresponding azacrown ethers. The solvent extraction of the divalent metal ions (Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+) and Pb(2+)) were exam...

Two acyclic Schiff-base ligands, bis-5,5′-(1,3-propanediyldiimino)-2,2-dimethyl-4-hexene-3-one and bis-5,5′-(1,3-ethanediyldiimino)-2,2-dimethyl-4-hexene-3-one, were used to complex homoleptic triethylaluminum and tris[bis(trimethylsilyl)amino]alu minum, respectively. The acid–base reactions proceeded in excellent yields with elimination of ethane or bis(trimethylsilyl)amine during in situ depr...