Twenty-four 2,2-di-n-butyl- and 2,2-diphenyl-6-aza-1,3-dioxa-2-stannabenzocyclononen-4-ones, each having a transannular N-->Sn bond, have been prepared by one-step reactions of alpha-amino acids (1 a-l), salicylaldehyde (2), and either di-n-butyltin(IV) oxide (3) or diphenyltin(IV) oxide (4). The new methodology constitutes an easy, highly efficient one-step synthesis of diorganotin(IV) derivat...

The structures of phenochalasins A and B were elucidated by spectroscopic studies including various NMR measurements. Phenochalasins A and B have the cytochalasan skeleton of the 21,23-dioxa, 17,22-dione moiety containing unique phenyl and O-methyl phenyl residues at the C-10 position, respectively.

In the isoquinoline ring system of the title mol-ecule, C(22)H(20)N(2)O(5), the N-heterocyclic ring is in a half-boat conformation. The dioxa-2-aza-spiro ring is essentially planar [maximum deviation = 0.026 (1) Å] and forms dihedral angles of 22.53 (5) and 64.46 (5)° with the benzene and phenyl rings, respectively. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen...

Titanium dioxide nanoparticles play a crucial role in the production of hydrogen gas evolution. Among four polymorphic phases TiO2 (anatase, rutile, brookite, and (B)), anatase phase shows good photo activity catalytic applications. We prepared single anatasephase usinga facile one-step ionothermal method with existence 1-(3,6-dioxa heptane) 3-methyl imidazolium methane sulfonate IL[DOMIMS]. Th...

The complexation reactions between N,N'-3,6-dioxa-1,8-octanebis (salicylaldimine) [saldioxen(I)] and Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) were studied spectrophotometrically in methanol solution at 25 °C. The stoichiometry of the complexes were obtained as 2:1 and 1:1 sadioxen-metal ion using mole ratio method. The formation constants of the complexes were determined, a...

The title compound, 5(2)-[(5-bromo-pent-yl)-oxy]-1(2),1(14),3(5),5(5)-tetra-tert-butyl-1(7),1(8),1(9),1(10)-tetra-hydro-1(6) H,1(16) H-1(4,12)-dibenzo[b,e][1,7]dioxa-cyclo-dodecina-3,5(1,3)-dibenzena-cyclo-hexa-phan-3(2)-ol, C54H73BrO4, was synthesized from the reaction of tert-butyl-calix[4]arene with 1,5-di-bromo-pentane using K2CO3 in CH3CN. The structure consists of a calixarene unit with a...

Leualacin is a new calcium channel blocker with a unique cyclic depsipeptide structure; it was isolated from a fungi Hapsidospora irregularis. The fermentation, isolation and characterization of leualacin have been reported in a previous paper1*. In this report, we describe the structure determination of leualacin (l l-benzyl-2,5,8-triisobutyl-10-methyll,7-dioxa-4,10,13-triazacyclohexadecane-3,...

The cycloisomerization reactions of allenes bearing cyclic acetal, thioacetal and dithioacetal subunits, when triggered either by the catalytic action of AgSbF6 or by one equiv. of CF3COOH, gave rise to four different classes of indeno-fused 1,4-dioxa, oxathia and dithia heterocycles, in most cases as a single diastereomer. Acyclic acetals and dithioacetals are also suitable starting materials ...