Dioxolane 2-phenyl

Condensation of vinyl chloride with formaldehyde and HCl (Prins reaction) yields 3,3-dichloro-l-propanol [83682-72-8] and 2,3-dichloro-l-propanol [616-23-9]. The 1,1-addition of chloroform [67-66-3] as well as the addition of other polyhalogen compounds to vinyl chloride are cataly2ed by transition-metal complexes (58). In the presence of iron pentacarbonyl [13463-40-6] both bromoform [75-25-2] CHBr, and iodoform [75-47-8] CHl, add to vinyl chloride (59,60). Other useful products of vinyl chloride addition reactions include 2,2-di luoro-4-chloro-l,3-dioxolane [162970-83-4] (61), 2-chloro-l-propanol [78-89-7] (62), 2-chloropropionaldehyde [683-50-1] (63), 4-nitrophenyl-p,p-dichloroethyl ketone [31689-13-1] (64), and p,p-dichloroethyl phenyl sulfone [3123-10-2] (65). 

The acid-catalyzed hydrolysis of 2-alkoxy-2-phenyl-l,3-dioxolanes has been studied. The initial step is rate-determining under eertain eonditions and is deseribed by the rate law given below, whieh reveals general acid catalysis. 

Dioxolanes, 312 4-Bromomethyl-1,3-dioxolane, 322 4-(3-Butenyl)-1,3-dioxolane, 323 4-Phenyl-1,3-dioxolane, 323 4-(4-Methoxyphenyl)-1,3-dioxolane, 324 4-(2-Nitrophenyl)-1,3-dioxolane, 324 4-Trimethylsilylmethyl-1,3-dioxolane, 324... 

Step G 4-fOrtho-(2, 3 -Dihydroxypropyloxycarbonyl)-Phenyl]-Amino-8-Trifluoromethyl-quinoHne Acetonide — 100 cc of toluene were added to 80 cc of 2,2-dimethyl-4-hydroxy-methyl-1,3-dioxolane and the toluene was distilled off under reduced pressure to eliminate the water present. To the anhydrous 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane thus obtained, 0.25 gram of an oily 50% suspension of sodium hydride and then 21.3 grams of 4-... 

B) A mixture of 2.4 parts of 1 acetyl-4-(4-hydroxyphenyl)piperazine, 0.4 part of sodium hydride dispersion 78% 75 parts of dimethylsulfoxide and 22.5 parts of benzene is stirred for one hour at 40°C. Then there are added 4.2 parts of cis-2-(2,4-dichlorophenyl)-2-(1 H-imidazol-1 -ylmethyl)-1,3-dioxolan-4-ylmethyl methane sulfonate and stirring is continued overnight at 100°C. The reaction mixture Is cooled and diluted with water. The product is extracted with 1,1 -oxybisethane. The extract is dried, filtered and evaporated. The residue Is crystallized from 4-methyl-2-pentanone. The product is filtered off and dried, yielding 3.2 parts (59%) of cis-1-acetyl-4-[2-(2,4-dichlorophenyl)-2-(1 H-imidazol-1-ylmethyl)-13-di-oxolan-4-ylmethoxy] phenyl] piperazine MP 146°C. 

S,55)-4,5-Bis(methoxymcthyl)-2-phenyl-1,3-dioxolan-2-yl]-3-buten-2-o) (5) Typical Proce-dure24-25 ... 

S,5S,2 S)-2-(l-Benzvloxyaminoalkyl)-4,5-bis methoxymethyl]-2-phenyl-l,3-dioxolanes General Procedure4-9 ... 

Methyl-2-phenyl-l,3-dioxolan — 1-Methoxy-l-phenyl-dthan 76°/0d.Th. 

CN 4-[4-[4-[4-[[2-(2,4-dichlorophenyl)-2-( 1H-1,2,4-triazol-1 -ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]-l-piperazinyl]phenyl]-2,4-dihydro-2-(l-methylpropyl)-3//-l,2,4-triazol-3-one... 

Dioxacycloalkanes are cyclic acetals that are used frequently as protective groups. Substituted derivatives have been synthesized to achieve easy removal. Simplest of all, the 4-phenyl-1,3-dioxolane has not been used commonly because cleavage needs electrolytic conditions. A mild hydrogenolysis method was developed in 1997 to make this protective group more popular (Scheme... 

Furthermore, it has been demonstrated in acetals of phenyl alkyl ketones that the presence of the aromatic moiety at the anomeric carbon induces a further stabilization resulting in very strong anomeric stabilization.29 This phenomenon is reminiscent of the stronger methyl substitution effects discussed above for 1,3-dioxolane and 1,3-dioxane (see also Table 1) than for alkyl ethers and alkanes. 

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