4-Phenyl-1,3-dioxane

S,5S,5 S)-5-(2-Alkfiiylmninoy or (4S,5S,5 S)-5-(2-Alkynylamino)-2,2-dimethy 1-4-phenyl-1,3-dioxane 9 3.91 g (10.5 mmol) of CeCI, 7H,(> is dried in vacuo at 140T70.5 lorr for 2 h. The following operations arc performed under argon protection. After cooling to r.t. 50 mL of anhyd THF is added and the resulting colorless slurry is stirred for 2 h under assistance of ultrasound. Subsequently, the suspension is cooled to... 

To the solution of (4S,5S, 5 S,)-5-(2-alkenylarnino)- or (4S,5S ,5 S )-5-(2-alkynylamino)-2,2,-dimethyl-4-phenyl-1.3-dioxane 9 obtained above in 30 raL of Et20 are added dropwise 30 mL of3N HC1 at 0 CC. Then the mixture is allowed to warm to r.t. over 12 h. The resulting precipitate is rccrystallizcd from CH2C12/Et20 (1 1) and treated with 2.5 N NaOH to provide the amino diol 10 which is extracted with 300 mL of Et,0 yield 81 87%. 

Table 1. Stereoselective Synthesis of a-Hydrogcnamino Acids Using 5-Amino-2,2-dimethyl-4-phenyl-1,3-dioxane as the Auxiliary51 53...

Recently, commercially available (45,5S)-5-amino-2,2-dimethyl-4-phenyl-1,3-dioxane has been successfully employed (177) in the synthesis (Scheme 10) of the chiral 13-crown-4, (55)-169, 16-crown-5, (SS)-170, and 19-crown-6, (SS)- , derivatives. 

Kern et al. found that, contrary to most heterocyclic monomers, TXN can be copolymerized with styrene (St) to random copolymers 149). Since that time the cationic copolymerization of TXN (and also DXL) with styrene has been studied by several groups but unfortunately GPC analysis was not commonly used and the only proof that copolymers were formed are based on solubility studies and on the presence of 4-phenyl-1,3-dioxane among the hydrolysis products of the products. Let us summarize the facts concerning TXN-styrene copolymerizations ... 

The presence of 4-phenyl-1,3-dioxane in the polymerizing mixture and among the copolymer hydrolysis products indicates that styrene is incorporated into the growing polyTXN chain and that attack occurs on the P-carbon atom of the double bond ... 

In essentially the same way 4-phenyl-1,3-dioxane may be formed by hydrolysis provided that St units are connected at both sides to oxymethylene units ... 

The less nucleophilic acetals copolymerize with vinyl compounds more readily. Perhaps, in these systems the alkoxycarbenium ions (... —OCH ) that coexist in equilibrium with oxonium ions facilitate copolymerization with vinyl compounds. Styrene copolymerizes with trioxane 51,52) and tetraoxane53). The latter system yields polytrioxane and trioxane-styrene copolymer together with 1,4-phenyl-1,3-dioxane. It was formed in 25% yield in ethylene dichloride at 30 °C after 1 hr using [BF3 OEtj] = 10-2 mol l-1, [styrene], = [tetraoxane = 0.5 mol l-1. The proposed mechanism of 4-phenyl- 1,3-dioxane formation is shown below (cf. also Chap. 7) ... 

Dioxans - Several syntheses of this ring are notable. In a modification of the Prins reaction, self-condensation of aliphatic aldehydes with styrene has given 4-phenyl-1,3-dioxans [such as ( 195)] in which the alkyl group is in the equatorial position.203 Good yields of the 1,3-dioxin-4-ones (196 R1 and R2 alkyl or aryl) have been obtained by reaction of aldehydes or ketones with diketene and Aliquat 336 (MeN[ (CH2 bMe] 3C1). 20 Condensation of aryl aldehydes with the diol (197) also gave good yields of the... 

Bertz showed that cuprates such as 460 added to cyclohexenone to give the 3-phenyl derivative (46 1) in optical yields of 0-50%Typical examples are R R N = (45,55)-(+)-5-amino 2,2-dimethyl-4-phenyl-1,3-dioxane (the reaction proceeded in 62% yield, 50% ee) (R) or (S) a-methylbenzylamine (70% yield, 30% ee) (R) or (5) a-(l-naphthyl)ethylamine (70% yield, 30% ee) and (-) a-2-naphthylethyl-amine (50% yield, 40%... 

Trimethyl-4-phenyl-1,3-dioxane CAS 5182-36-5 EINECS/ELINCS 225-963-6 Classification Cyclic acetal... 

Tri methyl hexyl formate Tri methyl hexyl propionate Trimethylphenethyl alcohol 2,3,6-Trimethylphenol 2,4,6-Trimethyl-4-phenyl-1,3-dioxane... 

Trimethyl-4-phenyl-1,3-dioxane 2,2,6-Trimethyl-a-propylcyclohexanepropanol 2,6,10-Trimethyl 5,9-undecadienal Undecatriene Verdyl acetate... 

Phenyl-2-cyclopenten-l-one -Phenyl-A/,APdielhanolamine 2-Phenyl-1,3-dioxane 4-Phenyl-1,3-dioxane... 

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