2-Methyl-1,6-dioxaspiro decan

Dioxaspiro[4.5l decane-2-methylamine 2-Methyl-2-thiopseudourea sulfate... 

From intermediate 43, the path to monensin would seemingly be straightforward. A significant task which would remain would be the construction of the l,6-dioxaspiro[4.5]decane substructure of monensin. You will note that the oxygen atoms affixed to carbons 5 and 12 in 43 reside in proximity to the ketone carbonyl at C-9. In such a favorable setting, it is conceivable that the action of acid on 43 could induce cleavage of both triethylsilyl ethers to give a keto triol which could then participate in a spontaneous, thermodynamically controlled spiroketalization reaction. Saponification of the C-l methyl ester would then complete the synthesis of monensin. 

Enantiomers of 7-methyl-1,6-dioxaspiro [4.5] decane 27 Decan-4-olide (Z,Z)-Octadeca-9,12-dienoic acid... 

Enantiomers of 2,7-dimethyl-l,6-dioxaspiro[4.5]decane 28 Enantiomers of 2-Ethyl-7-methyl-l,6-dioxaspiro[4.5]decane 29 Enantiomers of 2,8-dimethyl-l,7-dioxaspiro[5.5]undecane 30 5 - Methylh eptan - 2 -ol (Z)-Non-3-en-l-ol 3,7-Dimethyloctan- l-ol Benzaldehyde 2-Phenylethanol Phenylacetonitrile Isobutyl benzoate Isopentyl benzoate Hexadecanoic acid 17-Hydroxyan drost-4-en-3-one (2)-Octadec-9-enoic acid... 

The pheromone components of the wasp Paravespula vulgaris, (2R, 5S)- and (2S, 5S)-2-methyl-l,6-dioxaspiro[4.5]decane, was synthesized diastereoselectively. ... 

I. Izquierdo Cubero, M. T. P. Lopez Espinosa, and A. C. Richardson, Enantiospecific synthesis from D-fructose of (2S,5R) and (2R,5R)-2-methyl-l,6-dioxaspiro[4.5]decane [The odour bouquet, minor components, of Paravespula vulgaris (L.)],./. Chem. Ecol., 19 (1993) 1265-1283. 

Since the advent of multipulse-NMR techniques, more detailed 1H-NMR studies on methylcyclo-hexanes547, phenylcyclohexanes548, neomenthyl halides549 and bicydo[4.4.0]decanes 550 551 have been undertaken. The two diastereomeric 4-fm-butyl-7,ll-diphenylspiro[5.5]undecane-1,9-diones (3) and (4) could be identified unambiguously552, and substituted spirodioxane cyclohexanes such as, 9- m-butyl-2-methyl-1.3-dioxaspiro[5.5]undecane (5), have also been investigated553,554. 

However, treatment of (2/ ,3/ )-8-rer/-butyl-2,3-dimethyl-l,4-dioxaspiro[5.4]decane with trimethyliodosilane and hexamethyldisilazane in dichloromethane, followed by deprotection of the silyl ethers with tetrabutylammonium fluoride gives, in a combined yield of 78%, diastereomeric (S)-l-[(l) ,2/i)-2-hydroxy-l-methyl-propoxy]-4-tm-butyl-l-cyclohexene and () )-methylpropoxyl]-4- CT7-butyl-l-cyclohexene in a ratio of 20 1 (by GC)83a. 

The preparation of alkyl methyl ethers may be readily effected under PTC conditions from the alcohol, dimethyl sulphate and 50 per cent w/w aqueous sodium hydroxide, employing tetrabutylammonium hydrogen sulphate as catalyst.95 The usefulness of this procedure has been extended, and optimum conditions have been described for the alkylation of a range of aliphatic alcohols using, for example, 1-chlorobutane or benzyl chloride.96 The PTC preparative examples described in Expt 5.73 are for the methylation, allylation, but-2-enylation and benzylation of, for example, 2-hydroxymethyl-l,4-dioxaspiro[4.5]decane (Expt 5.63), and have been developed in the editors laboratories. These methods have also been applied to the alkylation of protected monosaccharide derivatives (p. 652). 

Kohnle U., Densbom S., Kolsch P., Meyer H. and Francke W. (1992b) -7-Methyl-l,6-dioxaspiro[4.5] decane in the chemical communication of European Scolytidae and Nitidulidae (Coleoptera). J. Appl. Ent. 114, 187-192. 

A mixture of 10.5 g of l,4-dioxaspiro[4.5]decane-2-methylamine and 8.6 g of 2-methyl-2-thiopseudourea sulfate in 40 ml of water was heated on the steam bath for 4 hours during which 2.0 g of methylmercaptan was collected in a dry ice bath connected to the reaction flask through a water cooled reflux condenser. The reaction mixture was then evaporated at 15 mm pressure to a solid residue which was then dissolved in 80 ml of 50/50 methanol-ethanol. The solution was filtered and evaporated to approximately 50 ml volume and allowed to cool and crystallize, giving a crop melting at 213.5°C to 215°C of l,4-dioxaspiro[4.5]decan-2-ylmethyl)-guanidine sulfate. 

A mixture consisting of 200 ml methyl alcohol, 1680 ml 40% aqueous dimethy-lamine solution, dimethyl ami nc HCl (303 g), and 200 g potassium cyanide (200 g) was added to l,4-dioxaspiro[4.5]decan-8-one (200 g), then stirred 65hours. A white suspension that formed was extracted four times with 800 ml diethyl ether, then concentrated, and the residue dissolved in 500 ml CH2C12. The organic phase was isolated, dried using Na2S04, then concentrated, and 265 g product isolated as a white solid. 

Bis(trifluoromethyl)benzoyl chloride (0.64mmol) was added to 8-phenyl-l,4-dioxaspiro[4.5]-decane-8-methanol (0.6 mmol) dissolved in 3 ml CH2C12 and the mixture stirred 16 hours at ambient temperature. The solution was then treated with triethylamine (0.6 mmol) and 4-dimethylamino pyridine (1 crystal), then stirred 1 hour at ambient temperature. The mixture was then retreated with 3,5-bis(trifluoromethyl)benzoyl chloride (0.32 mmol), then stirred additional 1 hour, and diluted with 10 ml water. The solution was extracted three times with 10 ml CH2C12 and combined fractions washed with brine, dried with MgS04, and concentrated. The residue was purified by flash chromatography with silica gel using isohexane/EtOAc, 5 1, and the product isolated in 78% yield as a colorless oil contaminated with about 10% (4-oxo-l-phenylcyclohexyl)-methyl 3,5-bis(trifluoromethyl)benzoate. 

Isopropyl-9-methyl-l,4-dioxaspiro[4,5]decane-2-methanol [63187-91-7], menthone glycerine acetal... 

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