Formaldehyde propiolactone from

P-Hydroxy acids lose water, especially in the presence of an acid catalyst, to give a,P-unsaturated acids, and frequendy P,y-unsaturated acids. P-Hydroxy acids do not form lactones readily because of the difficulty of four-membered ring formation. The simplest P-lactone, P-propiolactone, can be made from ketene and formaldehyde in the presence of methyl borate but not from P-hydroxypropionic acid. P-Propiolactone [57-57-8] is a usehil intermediate for organic synthesis but caution should be exercised when handling this lactone because it is a known carcinogen. 

However, note that not all of the regular polymers are able to form stereoisomers. In the case of polymers obtained from monomers not containing prochiral or chiral carbon atoms, such as, for example, ethylene, formaldehyde, ethylene oxide or /i-propiolactone, no stereochemical considerations are possible, since there are two identical substituents, and not different ones, at the monomer carbon atom. This is exemplified by the following ... 

Cell cultures provide infected fluids that contain little debris and can generally be satisfactorily clarified by filtration. Because most viral vaccines made from cell cultures consist of live attenuated virus, there is no inactivation stage in their manufacture. There are, however, two important exceptions inactivated poliomyelitis virus vaccine is inactivated with dilute formaldehyde or (3-propiolactone and rabies vaccine is inactivated with (3-propiolactone. The preparation of these inactivated vaccines also involves a concentration stage — by adsorption and elution of the virus in the case of poliomyelitis vaccine and by ultrafiltration in the case of rabies vaccine. When processing is complete the bulk materials may be stored until needed for blending into final vaccine. Because of the lability of many viruses, however, it is necessary to store most purified materials at temperatures of —70°C. 

Acrylic acid, CH2=CHCOOH, can be produced by a series of processes direct oxidation of acrolein oxidation of ethylene to ethylene oxide, with further reaction with hydrogen cyanide to ethylene cyanhydrin, which is then saponified and dehydrated addition of carbon monoxide and water to acetylene and from acetone by pyrolysis to ketene and addition of formaldehyde to the ketene to produce jS-propiolactone. jS-Propiolactone polymerizes to the corresponding polyester, which depolymerizes at 150 C to acrylic acid ... 

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