2-trichloromethyl-1,3-dioxolane

Under analogous conditions, carbonylation of chloral affords cis or trans 2,5-bis(trichloromethyl)-l,3-dioxolan-4-ones. The stereochemical outcome of the reactions can be controlled by the concentration of the employed sulfuric acid (90-99%) and the reaction time. The cis isomer is predominantly formed under more acidic conditions after 10 min (cis/trans 95/5 48% yield), whereas complete isomerization to the trans isomer (cisltrans 0/100 65% yield) takes place at lower acidity (90%) and prolonged reaction time (7 h) [63]. 

Hydrodehalogenation. A method for preparing exo-2-methyl-l,3-dioxolanes of carbohydrates via the trichloromethyl derivatives has been described. Unlike acetalization with acetaldehyde, the bulky trichloromethyl group originating from chloral has a great tendency to be cxo-oriented. Dechlorination with Bu,SnH accomplishes the purpose. ... 

The monomers 4-methyl-l,3-dioxene-4 and 2-trichloromethyl-4-methylene-l,3-dioxolane and other 4-methylene-l,3-dioxolanes are known to also undergo spontaneous copolymerization, with MA at temperatures >50 C, giving good yields of low-molecular-weight, alternating copolymer. The equimolar 4-methyl-l,3-dioxene-4-MA copolymer structure 11 is shown below. 

Both linear and cyclic acetals with vinyl residues copolymerize in an alternating fashion with MA. Two good examples are the copolymers prepared from the O-vinyl acetals of formaldehyde or acetaldehyde and 2-vinyl-l,3-dioxalane. The monomer 4-methylene-2-(trichloromethyl)-l,3-dioxolane also copolymerizes in a 1 1 fashion with MA, regardless of the initial monomer feed ratio in the reaction mixture, duration of reaction time, and monomer conversion. l,3-Dioxep-5-enes are also cyclic acetals. The copolymerization of these monomers with was discussed in... 

Poly(2-trichloromethyl-4-methylene-1,3-dioxolane-alt-MA), 321, 327 Poly(trimethylallylsilane-alt-MA), 311 Poly(2,4,4-trimethyl-l-pentene-alt-MA), 338, 586 properties, 433, 436... 

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