4,7-Dioxaspiro heptanes

C14H23NO5 7574-86-9) see Dopexamine (25)-3-oxo-l,4-dioxaspiro[4.S]decane-2-acetic acid (C,oH 405 153011-57-5) see Orlistat 3-oxo-2,7-dioxa-5-thiabicyclo[2.2.1]heptane (C4H4O3S 161683-18-7) see Lamivudine 17-oxo-4-estrene... 

In alkaline solution, 3-bromo-2,2-bis(bromomethyl)propanol undergoes successive loss of bromide to produce 2,6-dioxaspiro(3,3)-heptane (Ezra et al. 2005) (Figure 1.25). 

Aldehydes and ketones also add to allenes to form oxetanes.ai0,111) Further reaction of the oxetanes produced with excited carbonyls results in dioxaspiro[3.3]heptane derivatives(111) ... 

In the case shown below, the initially formed oxetane 54 further reacted with ben-zophenone forming 1,5- and 2,5-dioxaspiro[3.3]heptane derivatives (55 and 56) [48],... 

The Paterno-Biichi reaction has been employed in the synthesis, often in high yield, of a large variety of substituted oxetanes. In addition to simple aliphatic and aromatic alkenes, cycloaddition of ketones to, for example, fumaronitrile,284 l,3-diacetylimidazolin-2-one288 [Eq. (73)], and allenes286 has been reported. Allenes yield both 1,5- and l,6-dioxaspiro[3.3]heptanes as well as the 2-alkylidene-oxetane this is illustrated for benzophenone and tetramethylallene in Eq. (74). Cycloaddition of ketones to ketenimines to form 2- and... 

Upon prolonged irradiation in the presence of an excess ketone, the monoadducts are converted into 1,5- and l,6-dioxaspiro[3.3]heptanes (e.g., 80a,b) [53]. The regioisomeric 2- and 3-imino-oxetanes could be prepared by photolysis of ketenimines in the presence of aliphatic or aromatic ketones [72]. 

Even more rare are photocycloadditions involving carbonyl compounds to allenes. Arnold has found that acetone and tetramethylallene can be irradiated to form a mixture of 2-alkylideneoxetane and 1,3- and l,6-dioxaspiro[3,3]heptane products (107 108 109 = 8 31 27), all resulting from initial attack of the carbonyl n,ir state on the central carbon linkage. Hammond subsequently repented a study in which alkylideneoxetane derivatives (111) were photoisomerized to cyclobutanes (110). 

A double Williamson reaction is observed when pentaerythrltol dichloride or dibromide is treated with aleoholio potaaslucn hydroxide, forming 2,6-dioxaspiro 3.3]heptane.K>.i A lower yield here of S0% iwemB to redect the greater ring strain of this system. 

Figure 5.2.11. Cellulose pyrolysate obtained at 59(P C and separated on a methyl silicone with 5% phenyl silicone type column. 1 acetic anhydride, 2 pentanal, 3 2-hydroxybutanedialdehyde, 4 1,4-dioxadiene, 5 tetrahydro-2-furanmethanol, 6 2-(hydroxymethyl)-furan, 7 3-methyl-2-hexanone, 8 2-methoxy-2,3-dihydrofuran, 9 2(5H)-furanone, 10 1-acetyloxypropan-2-one, 11 hydroxycyclopentenone, 12 5-methylfurfural, 13 2,3-dihydro-5-methylfuran-2-one, 14 1-cyclopentylethanone, 15 2-hydroxy-3-methyl-2-cyclopenten-1-one, 16 3,5-dimethylcyclopentan-1,2-dione, 17 unknown, 18 3-ethyl-2,4(3H,5H)-furandione, 19 6-methyl-1,4-dioxaspiro[2,4]heptan-5-one, 20 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one, 21 1,4 3,6-dianhydro-a-D-glucopyranose, 22 5-(hydroxymethyl)-furfural, 23 4-cyclopenten-1,2,3-triol, 24 5-ethyl-3-hydroxy-4-methyl-tetrahydrofuran-2-one, 25 levoglucosan, 26 1,6-anhydro-p-D-glucofuranose.

Stirring l,l-dibromo-2-phenylcyclopropane in a dimethyl sulfoxide solution of potassium tert-butoxide and ethylene glycol afforded l-phenyl-4,7-dioxaspiro[2.4]heptane (2) in 73% yield, whereas /er/-butyl 2,2-bis(phenoxy)cyclopropanecarboxylate (3) was obtained in 69% yield from tcrt-butyl 2,2-dichlorocyclopropanecarboxylate under phase-transfer conditions using triethylbenzylammonium chloride as catalyst. A further example is given in ref 659. 

Sodium benzenethiolate reacted with 6,6-dimethyl-2-vinyl-5,7-dioxaspiro[2.5]octane-4,8-dione (16) to give the 1,5-addition product only. When ethyl trani-6-(l-heptenyl)-2-oxo-bicyclo[3.1.0]heptane-l-carboxylate (18, R = Et) was treated with potassium benzenethiolate it was converted stereospecifically to the corresponding trawj -cyclopentanone derivative 19 (R = Et) with a defined configuration at the a-carbon atom of the side chain. This reaction proved to be useful for the stereoselective synthesis of prostaglandins. ... 

A further development of this methodology is a novel route to 3-vinylcyclohexanone derivatives which is based on the diphenyl disulfide catalyzed combination of 5,5-diphenyl-l-vinyl-4,7-dioxaspiro[2.4]heptane (42) with substituted alkenes (see Section 2.4.4.). 

Spirit of glyceryl trinitrate. See Nitroglycerin Spirit of Hartshorn. See Ammonium hydroxide Spirit of nitrous ether. See Ethyl nitrite Spirit orange. See Solvent yellow 14 Spirits of salt. See Hydrochloric acid Spirits of turpentine. See Turpentine Spirits of wine. See Alcohol Spirit of trinitroglycerin. See Nitroglycerin Spirit of turpentine. See Turpentine Spiro (benzofuran-2(3H), 1 -(2) cyclohexene)-3,4 -dione, 7-chloro-2, 4,6-trimethoxy-6 -p-methyl-. See Griseofulvin Spiro [bicycio [3.1.1] heptane-2,2 -oxirane], 6,6-dimethyl-. See Epoxypinane Spiro [1,3-dioxane-5,2 (2H)-napthalene], hexahydro-2,5, 5 -trimethyl-. See Dimethyl hexahydronaphthyl dihydroxymethyl acetal Spirofior. See 3-Ethyl-2,4-dioxaspiro (5.5) undec-8-ene... 

Chloro-3-chloromethylbutane-l,3-diol heated to 160 -> 3-chloromethyl-3-hydroxytetrahydrofuran (Y ca. 100%) treated with NaOH (or Na-ferf-butoxide) in ether at 20-30° 1,5-dioxaspiro [2.4] heptane (Y over 80%). E. Steininger, Ang. Gh. 77, 455 (1965). 

Read [5] in 1912 reported obtaining an apparently high molecular weight solid by the strongly acid-catalyzed reaction of pentaerythritol and glyoxal. In 1951 Orth [6] reacted terephthaldehyde or 1,4-cyclohexanedione with 2,6-dioxaspiro[3,3]heptane to give polyspiroacetal resins [Eq. (5)]. In 1962 Cohen and Lavin [7-9] prepared similar polyspiroacetal resins from pentaerythritol and dialdehydes. 

Dry HCl passed into a soln. of 4,7-dioxaspiro[2,4]heptane in dry CCI4 whereupon the temp, readies ca. 40°, the product isolated after the soln. has been allowed to return to room temp. product. Y 90%. F. e. s. G. Giusti, Bl. 1972, 4335. 

Across C=0 Bonds The photochemical [2-1-2] cycloaddition reactions of allenes with aldehydes and ketones respectively, afford the four-membered ring cycloadducts, which usually add a second equivalent of the ketone to give dioxaspiro[3,3]heptanes. For example, from tetramethylallene and acetone, the [2-1-2] cycloadduct 225 (8 %) and the spiro compounds 226 (57 %) and 227 (27 %) are obtained... 

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