Glycols 1.3- dioxolan-2-ones

The acetals you have met so far were formed by reaction of two molecules of alcohol with one of carbonyl compound. Cyclic acetals, formed by reaction of a single molecule of a diol, a compound containing two hydroxyl groups, are also important. When the diol is ethylene glycol (as in this example) the five-membered cyclic acetal is known as a dioxolane. ethylene glycol... 

CF,C02)2lPh, H2O, CH3CN, 85-99% yield. In the presence of ethylene glycol the dithiane can be converted to a dioxolane (91% yield) or in the presence of methanol to the dimethyl acetal. The reaction conditions are not compatible with primary amides. Thioesters are not affected. A phenylthio ester is stable to these conditions, but amides are not. The hypervalent iodine derivative l-(t-butylperoxy)-l,2-benziodoxol-3(l/f)-one similarly cleaves thioketals."... 

Reaction of ketones such as 1-menthone 398 with silylated glycolic acid 417 in the presence of catalytic amounts of TMSOTf 20 provides an lil-mixture of the l,3-dioxolan-4-ones 418 and 419 [35, 36]. Likewise, other aldehydes and ketones [37, 38] and pivaldehyde [39] react with substituted silylated glycohc adds 420 a, b and yS-hydroxy acids 420c to give, e.g., 421 a, b and 421c as mixtures [37-40]. Reaction of pivaldehyde with the persilylated hydroxy acid 420 d and TMSOTf 20 to... 

Figure 7.2.1. Cellulose pyrolysate obtained at 59CP C and trimethylsilylated. The separation was done on a methyl silicone with 5% phenyl silicone type column. 1 1,2-dihydroxyethane, 2 2-hydroxypropionic (lactic) acid, 3 hydroxy acetic (glycolic) acid, 4 turanmethanol, 5 peak from silylation reagents, 6 1,3-dihydroxypropanone, 7 1,4-dioxane-2,5-diol, 8 1,3-dioxolane-4,5-diol, 9 1,3-dihydroxybenzene, 10 2-methyl-1,4-dioxane-2,5-diol, 11 1,4-dihydroxybenzene, 12 3-hydroxy-2-(hydroxymethyl)-2-cyclopenten-1-one, 13 2-hydroxy-5-(hydroxymethyl)-4(H)-pyran-4-one, 14 1,2,3-trihydroxybenzene, 15 internal standard, 16 an anhydrosugar, 17 levoglucosan (1,6-anhydro-p-D-glucopyranose), 18 a monosaccharide, 19 an anhydrosugar, 20 an anhydrosugar, 21 1.6-anhydro-P-D-glucofuranose .

The relation between SDAs and the zeotype structures they direct is not simply bijective. Usually, the formation of a certain zeotype structure can be directed by more than one SDA [5]. For example, the sodalite structure shown in Fig. 1 can also be directed by molecules other than trioxane, namely, 1,3-dioxolane [15], 1,3-dioxane [16], ethylene glycol [17], ethanolamine [18], and ethylenediamine [18]. Also, depending upon the reaction conditions, an organic molecule may direct the formation of different frameworks [8, 9]. It has therefore been proposed that the term "template", formerly used instead of SDA, should now be reserved for cases of strong structure direction and strong host-guest relationships, in line with its usage in other areas of the natural sciences [5]. A strict condition for a true "template" is that it should not exhibit disorder in the voids of the silica host. 

Methyl-2,6-di-t-butylphenol Methyl di-t-butylphenol. See BHT 4-Methyl-7-(diethylamino) coumarin. See 7-Diethylamino-4-methylcoumarin Methyl diglyme. See Diethylene glycol dimethyl ether Methyl digol. See Methoxydiglycol Methyl 1,1-dimethylethyl ether. See Methyl t-butyl ether 4-Methyl-1,3-dioxolan-2-one. See Propylene carbonate Methyl dodecanoate Methyl n-dodecanoate Methyl dodecylate. See Methyl laurate... 

CAS 108-32-7 EINECS/ELINCS 203-572-1 Synonyms Carbonic acid, cyclic propylene ester Carbonic acid, 1,2-propylene glycol ester 1,3-Carbon dioxypropane Cyclic methyleth-ylene carbonate Cyclic propylene carbonate Cyclic 1,2-propylene carbonate 1,3-Dioxolan-2-one, 4-methyl Dipropj ene carbonate 4-Methyl-1,3-dioxolan-2-one 1-Methyl ethylene carbonate 1,2-Propanediol carbonate 1,2-Propanediyl carbonate 1,2-Propylene carbonate Propylene glycol cyclic carbonate Classification Qrganic compd. carbonic acid ester Empirical C,HsQ,... 

CAS 96-49-1 EINECS/ELINCS 202-510-0 Synonyms Carbonic acid, cyclic ethylene ester 1,3-Carbonyldioxyethane Cyclic ethylene carbonate 1,3-Dioxolan-2-one Dioxolone-2 1,2-Ethanediol carbonate Ethylene carbonic acid Ethylene glycol carbonate Ethylene glycol cyclic carbonate Glycol carbonate Classification Carbonic acid ester Empirical C3H4O3 Formula (-CH20)2C0... 

N-Methyl-N,N-dioctyl-1-octanaminium chloride. See Tricaprylyl methyl ammonium chloride 8-Methyl-3,6-dioxa-1-undecanol. See Diethylene glycol methylpentyl ether 2-Methyl-1,3-dioxolane-2-acetic acid ethyl ester. See Ethyl acetoacetate ethylene ketal 4-Methyl-1,3-dioxolan-2-one. See Propylene carbonate... 

Ethyl carbonate (glycol carbonate, 1,3-dioxolan-2-one) n. A solvent for many polymers and resins. Syn diethyl carbonate. 

Propylene carbonate (l,3-dioxolan-2-one, methyl-) Propylene glycol (1,2-propanediol)... 

In addition to their use as protecting groups, dioxolanes have been employed as intermediates. One example is a ring expansion of cyclopentanones via Grob fragmentation of the acetal (eq 14). A novel synthesis of glycerol from formaldehyde and ethylene glycol involves dioxolane intermediates. ... 

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