Synthesis of a 1,2,7,8-Tetraoxa-spiro[5.5]undecane

Synthesis of a new spiro organic peroxide is described. The peroxy bonds were incorporated into the substrate framework via an acid-catalyzed ketal exchange reaction using hydrogen peroxide as the source of peroxy linkage. The hydroperoxyl groups were then bonded at the OH ends via Hg（II）-induced electrophilic additions to the C-C double bonds, giving a novel sprio structure with one peroxy bond in each of the two six-membered rings. The ester functionalities in the side chains also make it possible to conduct further structural modifications.     

Chiral macrocyclic polyethers incorporating a tetraoxaspiro[5.5]undecane or trioxa-azaspiro[5.5]undecane moiety

New macrocyclic polyethers possessing chirality due to a spiro ring junction are prepared from 2,8-dihydroxymethylated (+)-1,4,7,10-tetraoxaspiro[5.5]undecane 1 and (+)-1,4,7-trioxa-10-azaspiro[5.5]undecane 2, both (E,E). N-Functionalization of compounds derived from 2 is also examined. The complexing properties of representative ligands 3, 4, 5 measured by spectrophotometry in THF, for alkaline and alkaline-earth cations, indicate that these spheric positively-charged species are weakly associated.     

Synthesis of the enantiomers of 1,7-dioxaspiro[5.5]undecane, 4-hydroxy-1,7-dioxaspirol[5.5]undecane and 3-hydroxy-1,7-dioxaspiroi[5.5]undecane : The components of the olive fruit fly pheromone

All of the enantiomers of the title compounds, the components of the pheromone of the olive fruit fly ($\text{Dacus}$$\text{oleae}$ Gmelin), were synthesized from ($\text{S}$)-malic acid.     

One-Step Synthesis of the 1-Azaspiro[5.5]undecane Skeleton Characteristic of Histrionicotoxin Alkaloids from Linear Substrates via Hg(OTf)2-Catalyzed Cycloisomerization

Histrionicotoxin (HTX) alkaloids isolated from the poison arrow frogs possess a unique structure characterized by a 1-azaspiro[5.5]undecane skeleton common to the HTX family. The unique molecular architecture of HTXs and the interest as potential target drugs have prompted synthetic chemists to promote the total synthesis so far. However, all of the synthetic strategies to access the 1-azaspiro[5.5]undecane framework of HTXs take a multistep approach from linear starting materials due to stepwise construction of either six-membered carbo- or azacycle. Herein, we report the direct one-step construction of the 1-azaspiro[5.5]undecane skeleton from linear amino ynone substrates bearing an N-methoxycarbonyl group utilizing our mercuric triflate (Hg(OTf)₂)-catalyzed cycloisomerization reaction. The utility of this novel methodology was demonstrated by the total and formal syntheses of HTX-235A and HTX-283A, respectively, from the azaspirocycle.     

Synthesis of the enantiomers of 1,7-dioxaspiro[5.5]undecane and 4-hydroxy 1,7-dioxaspiro[5.5]undecane,the components of the olive fly pheromone

The enantiomers of the olive fly pheromone (1 and 4) were synthesized from ($\text{S}$)-malic acid in amounts sufficient for the biological test.     

Synthesis and Stereochemistry of Novel Dibrominated 1,5-Dioxaspiro[5.5]undecane Derivatives

 The synthesis and stereochemistry of new dibrominated spiro-1,3-dioxane derivatives are reported. Investigations by means of NMR methods and single crystal X-ray diffraction for two compounds revealed the high regio- and diastereoselectivity of the bromination reaction of some new spiro-1,3-dioxanes and the asymmetric induction of the chiral carbon atom located in the spiro skeleton.     

Synthesis and Stereochemistry of Novel Dibrominated 1,5-Dioxaspiro[5.5]undecane Derivatives

Summary.  The synthesis and stereochemistry of new dibrominated spiro-1,3-dioxane derivatives are reported. Investigations by means of NMR methods and single crystal X-ray diffraction for two compounds revealed the high regio- and diastereoselectivity of the bromination reaction of some new spiro-1,3-dioxanes and the asymmetric induction of the chiral carbon atom located in the spiro skeleton. Received July 13, 1999. Accepted October 21, 1999     

Stereoselective synthesis of 2e-phenyl-4e-hydroxy-1-azaspiro[5.5]undecane

6-Phenylspiro(1-aza-7-oxabicyclo[2.2.1]heptane-2-cyclohexane) was synthesized by cyclization of N-benzylidene-1-allyl-1-cyclohexylamine N-oxide, and its reduction splitting yielded 2e-phenyl-4e-hydroxy-1-azaspiro[5.5]undecane.Russian People's Friendship University, Moscow 117198. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 77–80, January, 1998.     

Synthesis of the optically active forms of 4,10-dihydroxy-1,7-dioxaspiro[5.5]undecane and their conversion to the enantiomers of 1,7-dioxaspiro[5.5]undecane,the olive fly pheromone

Both the enantiomers of l,7-dioxaspiro[5.5]undecane, the major component of the pheromone of the olive fly (Dacus oleae), were synthesized from (S)-malic acid.     

The reaction of dihydroxyacetone with ethanedithiol. Synthesis and x-ray crystal structure of 1,4,7,10-tetrathiaspiro[5.5]undecane

Reaction of dihydroxyacetone with an excess of ethanedithiol in the presence of 10M hydrochloric acid gives 2,2-di(hydroxymethyl)-1,3-dithiacyclopentane ( 1 ) in low yield. When boron trifluoride etherate is used instead of hydrochloric acid, the same reactants give 1,4,7,10-tetrathiaspiro[5. 5]undecane ( 3 ). The structure of the latter was established by X -ray crystallography. The crystals are monoclinic, space group P2,/n, with a = 6.31(1), b = 21.57(2), c = 7.61(1)Å, β = 102.2(1)° and Z = 4, R = 0.038 for 2289 reflections. The two 1,4-dithiane rings in 3 are significantly more puckered than normal cyclohexane rings. The uv spectrum of 3 is consistent with values reported for other sulphides and with the X-ray structure.     

Synthesis and reactions of 3,9-diisocyanates and diisothiocyanates in the 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] undecane series

The synthesis of several novel phosphorus-containing isocyanates and isothiocyanates is reported. These compounds are spiranes with two six-membered dioxaphosphorinane rings in their respective molecule. The phosphorus-bonded isocyanato and isothiocyanato groups are capable of undergoing addition reactions with active hydrogen atom-containing compounds.     

Synthesis of monomers that expand on polymerization. Synthesis and polymerization of 3,9-dimethylene-1,5,7,11-tetraoxaspiro[5.5]undecane

A spiro ortho-carbonate containing two double bonds, 3,9-dimethylene-1,5,7,11-tetraoxaspiro[5.5]undecane (III) was prepared from 2-methylene-1,3-propanediol (VI). The structure of the monomer was indicated by its elementary analysis as well as its infrared and NMR spectra. When the crystalline monomer was polymerized with Lewis acids such as trifluoride etherate as catalysts, soluble polymer with a high molecular weight was obtained. The infrared and NMR spectra indicated that the polymer was an alternating copolymer of ether and carbonate having double bonds. When the usual monomers such as vinyl chloride and styrene polymerize, shrinkage occurs. However, this monomer underwent expansion on polymerization.     

Energetics of oxaspirocycle prototypes: 1,7-dioxaspiro[5.5]undecane and 1,7,9-trioxadispiro[5.1.5.3]hexadecane

The relative gas-phase energetics of several low-lying isomers of 1,7-dioxaspiro[5.5]undecane and 1,7,9-trioxadispiro[5.1.5.3]hexadecane have been calculated with second-order Mller-Plesset perturbation theory and basis sets as large as aug-cc-pVQZ. Relative energies in THF, dichloromethane, acetone, and DMSO have been estimated with corrections from polarized continuum model calculations at the B3LYP/6-311+G(d) level. In the most stable conformation of 1,7-dioxaspiro[5.5]undecane, both rings adopt chair conformations, and both oxygens are axially disposed (2A). It is more than 2 kcal mol(-1) more stable than all the other conformers. In agreement with previous work, the "twist-boat" trans isomer (3A) is the most stable isomer of 1,7,9-trioxadispiro[5.1.5.3]hexadecane. However, in contrast to this earlier study, an "all-chair" conformation (3B) is found to be the most stable cis isomer of 1,7,9-trioxadispiro[5.1.5.3]hexadecane (E approximately 0.5 kcal mol(-1) in acetone and DMSO). Gauge-independent atomic orbital computations at the B3LYP/6-311+G(d) level indicate that this is the only cis isomer with (13)C NMR chemical shifts that are qualitatively consistent with the experimental spectra.     

Synthesis and structural analysis of new macrocycles exhibiting 3,9-dimethyl-3,9-diaryl-2,4,8,10-tetraoxaspiro[5.5]undecane units

The template synthesis of a new series of macrocycles (from monomers to tetramers) with 2,4.8,10-tetraoxaspiro[5.5]undecane units is reported. The structural analysis of the compounds is carried out using the data of high field NMR investigations, mass spectrometry studies (FAB, MALDI and ESI-MS) and the solid state X-ray diffractometry molecular structures for three compounds.     

An Improved Synthesis of Bicyclo[3.3.3]undecane

A shorter and significantly higher-yield procedure for the preparation of bicyclo[3.3.3]undecane (manxane) is reported.     

Synthesis of the enantiomers of 3-hydroxy-1,7-dioxaspiro[5.5]undecane, a minor component of the olive fly pheromone

(3$\text{R}$,6$\text{R}$)-(?)-3-Hydroxy-1,7-dioxaspiro[5.5]undecane 3a and its antipode were synthesized from ($\text{S}$)-malic acid.