Thiocyanato-substd. ester derivs. prodn. - by reacting diol cpds. with orthoester(s) followed by isothiocyanate cpds., useful in prodn. of insecticides, pharmaceuticals etc

In the prodn. of thiocyanato esters of formula (I), a diol formula (II) is reacted with an ortho-ester of formula (III) or ketene acetal of formula (IIIa) and the resulting cpd. of formula (IV) is reacted with an isothiocyanate, opt. in the presence of a catalyst and an inert organic solvent. In the formulae, R1-6 are H, opt. substd. alkyl, cycloalkyl, alkenyl, aralkyl or aryl, and R3 and R4 can additionally be halogen, CN, alkoxy or aryloxy; or R1 and R2 and opt. substd. ring n is 0 or 1; R7 is H, opt. substd. alkyl, alkenyl, aralkyl, aryl, alkoxy or alkoxycarbonyl; and R8, R9 and R10 are opt. substd. alkyl, alkenyl, aralkyl or aryl. (I) are stable cpds. which may be hydrolysed to the corresponding hydroxythiocyanates, which are useful as intermediates for pesticides and pharmaceuticals (antidiabetic agents) and as insecticides. Redn. of (I) gives mercapto-alcohols useful as intermediates for herbicides and insecticides. (I) may also be thermally rearranged to isothiocanates useful as intermediates for thioureas. The new process is also useful for the prodn. of thiosaccharides.