Verfahren zur Herstellung von Peroxyketalen

1,138,234. Peroxyacetals and peroxyketals. MONTECATINI SOC. GENERALE PER L'INDUSTRIA MINERARIA E CHIMICA. 16 May, 1966 [21 May, 1965], No. 21681/66. Heading C2C. Peroxyacetals or peroxyketals are prepared by reacting an alkyliden-diperoxide with a mono- or di-hydric alcohol until up to 1 mol. of hydroperoxide by-product per mol. of starting alkyliden-peroxide has been formed. The peroxyacetals and peroxyketals have the formulµ and respectively in which R 1 is an alkyl or aralkyl group containing up to 10 carbon atoms; R 2 and R 3 are hydrogen, or an alkyl or cycloalkyl group which may be alkyl- or halogen-substituted and which contains up to 10 carbon atoms, or R 2 or R 3 forms the group in which R 6 is hydrogen or an alkyl or cycloalkyl group which may be alkyl or halogen substituted and contains up to 10 carbon atoms; or R 2 and R 3 together with the carbon atom to which they are attached form a carbocyclic ring; R 4 is a primary or secondary alkyl group, aralkyl or a cycloalkyl group containing up to 10 carbon atoms; R is hydrogen or an alkyl, cycloalkyl or aralkyl group containing up to 10 carbon atoms; and R 5 is a bivalent alkylene, cycloalkene or arylene group containing up to 10 carbon atoms and which may be substituted by an alkyl group or a halogen atom. In the preferred embodiment of the invention an alkylidene diperoxide of formula is reacted with a monohydric alcohol R 4 OH or with a dihydric alcohol having the formula and the reaction is stopped by cooling when up to 1 mol. of R 1 O-OH (hydroperoxide) per mol. of starting alkylidendiperoxide has been formed as a by-product. Examples are given of the preparation of (a) 2-methoxy-2-tert.-butylperoxy - butane; (b) 2 - methoxy - 2 - tert. - butylperoxy - propane; (c) 2 - ethoxy - 2 - tert. - butyl - peroxy - propane; (d) 2 - (2 - ethyl - hexyloxy)-2-tert.-butyl-peroxy-propane; (e) 2- benzyloxy - 2 - tert. - butyl - peroxy - propane; (f) the compound (g) a mixture of 2,2-di-tert.-butylperoxy-propane; 2 - methoxy - 2 - tert. - butyl - peroxypropane and acetondimethylacetal; (h) 2,2- di - tert. - butyl - peroxy - propane and (j) 1-methoxy-1-tert.-butylperoxy-cyclohexane.