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.     

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.     

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.     

2,8-二甲基-1,7-二氧杂螺[5,5]十一烷的合成

果蝇 ( Tephritidae)对水果生产有严重的危害 .热带果蝇寿命较长 ,具有很强的迁徙能力和繁殖能力 .因此开展果蝇生物防治和控制措施的相关研究具有重要的意义 [1,2 ] .Baker等 [3]发现性成熟的雌B.dorsalis果蝇 ,性腺分泌物中包含有螺环缩酮化合物 2 ,8-二甲基 - 1 ,7-二氧杂螺 [5 ,5 ]十一烷 ( 1 ) .Bactrocera Latifrons( Hendel)果蝇的雄性腺体分泌物中也存在螺环缩酮 1 [4 ] ,另外在 rove甲虫腹梢分泌物中也分离出 1 [5] ,螺环缩酮不仅作为性信息素组分存在于许多果蝇腺体中 ,而且作为结构单元存在于许多复杂的有强烈生理活性的天然…     

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.     

Spiroketals: a total synthesis of (±)-talaromycin B via a stereoselective cation-olefin cyclisation step

The acid catalysed rearrangement of an acetal derived from 2-hydroxymethyl-3-butene-l-ol proceeding via an intramolecular cation-olefin cyclisation provides access to a 4-hydroxytetrahydropyran and thence to (±)-talaromycin B.     

Sex pheromone biosynthesis in the female olive fruit-fly. Double labelling from [18O2]-dioxygen into 1,7-dioxaspiro[5.5]undecane

The demonstration that both oxygen atoms of 1,7-dioxaspiro[5.5]undecane (1), the sex-pheromone of the female olive fly, originate from dioxygen, strongly implicates monooxygenase mediated processes in assembly of (1), and reveals unexpected complexity in the formation of its nine-carbon precursor.     

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.     

Effect of Freon matrices on the intermediates stabilized in X-ray irradiated 1,7-dioxaspiro[5,5]undecane solutions at 77 K

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Regioselective synthesis of 1,7-dioxaspiro[4.4]nonanes from a trimethylenemethane dianion synthon

2-Chloromethyl-3-(2-methoxyethoxy)prop-1-ene behaves as a versatile trimethylenemethane dianion synthon, precursor of a variety of methylidenic diols obtained by DTBB-catalysed lithiation in the presence of a carbonyl compound (E¹=R¹R²CO) in THF at −78 to 0 °C, followed by the addition of an epoxide [E²=R³R⁴C(O)CHR⁵] at 0 to 20 °C and final hydrolysis. These diols undergo double intramolecular iodoetherification in the presence of iodine and silver(I) oxide in THF or dioxane-water, to give the corresponding 1,7-dioxaspiro[4.4]nonanes, which can be easily oxidised to a variety of 1,7-dioxaspiro[4.4]nonan-6-ones. These skeletons are present in a wide series of natural products.     

Synthesis of three stereoisomeric forms of 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane,the main component of the cephalic secretion of andrena wilkella

Three stereoisomers of 2,8-dimethyl-1,7-dioxaspiro[5,5]undecane were synthesized from acetoacetic ester by utilizing its yeast reduction and dianion alkylation.     

Dioxolane-to-bridged acetal-to-spiroketal via ring-closing metathesis and rearrangement: a novel route to 1,7-dioxaspiro[5.5]undecanes

Several examples of 1,7-dioxaspiro[5.5]undecane spiroketal systems have been synthesized from the common bicyclic intermediate 1 via acid-catalyzed rearrangement. Intermolecular ketalization of C(2) symmetric diene diol 3 with ketone 9 and then desymmetrization by ring-closing metathesis rapidly constructs bicyclic acetal 1. The locked conformation and steric bias of 1 allow stereoselective functionalization of one or both double bonds before spiroketalization.     

Flexible synthesis of enantiomerically pure 2,8-dialkyl-1,7-dioxaspiro[5.5]undecanes and 2,7-dialkyl-1,6-dioxaspiro[4.5]decanes from propargylic and homopropargylic alcohols

A new approach to enantiomerically pure 2,8-dialkyl-1,7-dioxaspiro[5.5]undecanes and 2,7-dialkyl-1,6-dioxaspiro[4.5]decanes is described and utilizes enantiomerically pure homopropargylic alcohols obtained from lithium acetylide opening of enantiomerically pure epoxides, which are, in turn, acquired by hydrolytic kinetic resolution of the corresponding racemic epoxides. Alkyne carboxylation and conversion to the Weinreb amide may be followed by triple-bond manipulation prior to reaction with a second alkynyllithium derived from a homo- or propargylic alcohol. In this way, the two ring components of the spiroacetal are individually constructed, with deprotection and cyclization affording the spiroacetal. The procedure is illustrated by acquisition of (2S,5R,7S) and (2R,5R,7S)-2-n-butyl-7-methyl-1,6-dioxaspiro[4.5]-decanes (1), (2S,6R,8S)-2-methyl-8-n-pentyl-1,7-dioxaspiro[5.5]undecane (2), and (2S,6R,8S)-2-methyl-8-n-propyl-1,7-dioxaspiro[5.5]undecane (3). The widely distributed insect component, (2S,6R,8S)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane (4), was acquired by linking two identical alkyne precursors via ethyl formate. In addition, [(2)H(4)]-regioisomers, 10,10,11,11-[(2)H(4)] and 4,4,5,5-[(2)H(4)] of 3 and 4,4,5,5-[(2)H(4)]-4, were acquired by triple-bond deuteration, using deuterium gas and Wilkinson's catalyst. This alkyne-based approach is, in principle, applicable to more complex spiroacetal systems not only by use of more elaborate alkynes but also by triple-bond functionalization during the general sequence.     

Intramolecular michael addition reaction to chiral vinylic sulfoxides. An enantioselective synthesis of (R)- and (S)-1,7-dioxaspiro[5.5]undecane

(R)- and (S)-1,7-Dioxaspiro[5.5]undecane ((R)-1 and (S)-1), sex pheromone of an olive fly, was each stereoselectively synthesized using an intramolecular Michael addition of hydroxyl group to a chiral vinylic sulfoxide moiety as an asymmetric induction step.     

Syntheses of Racemic and Optically Active 4-Hydroxy-2-hydroxymethyl-1,7-dioxaspiro[5.5]undecanes

Racemic and optically active 4-hydroxy-2-hydroxymethyl-1,7-dioxaspiro[5.5]undecanes were prepared in six steps from butane-1,2,4-triol and valerolactone with the longest linear sequence being four steps.     

A new 3-methylidenepentane-1,5-dianion synthon: synthesis of perhydropyrano[2,3-b]pyrans and 1,7-dioxaspiro[4.5]decanes

4-Phenylsulfanyl-2-(2-phenylsulfanylethyl)but-1-ene (2) has proved to be an appropriate and new 3-methylidenepentane-1,5-dianion synthon. The reaction of 2 with an excess of lithium powder and a catalytic amount of DTBB (2.5%) in the presence of a carbonyl compound in THF at 0 °C, leads, after hydrolysis, to the expected methylidenic diols 3. These diols when subjected to successive hydroboration-oxidation and final oxidation, undergo spontaneous cyclisation to furnish a series of cis-perhydropyrano[2,3-b]pyrans (4) in a highly diastereoselective manner (>99% de). Additionally, diols 3 also undergo double intramolecular iodoetherification promoted by a silver salt, to furnish the corresponding 1,7-dioxaspiro[4.5]decanes (6) in very high yields.     

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.