Abstract: A process for preparing insecticidal N-acyl-tetrahydro-2-nitromethylene-2H-1,3-thiazines, intermediates involved therein and certain of the products.

Abstract: Novel phosphoric acid esters of the formula ##STR1## where R.sup.1 is alkoxy of a maximum of 4 carbon atoms or phenyl, R.sup.2 is alkyl of a maximum of 3 carbon atoms, alkoxy or alkylthio of a maximum of 4 carbon atoms, or alkylamino or dialkylamino, each alkyl being of a maximum of 4 carbon atoms, R.sup.3 is methyl, ethyl, hydrogen or chlorine, R.sup.4 and R.sup.5 are phenyl or alkyl of a maximum of 4 carbon atoms, or are, together with the nitrogen atom, a 5- to 7-membered heterocycle, and X is oxygen or sulfur, with the proviso that R.sup.1 is not phenyl when R.sup.2 is alkyl. The compounds are suitable for combating pests.

Abstract: Thebaine is converted to a mixture of codeinone and neopinone in aqueous formic acid solution containing as catalyst a mercuric salt. Thebaine is converted to a neopinone ketal by irradiation in an alkanol or to a mixture of neopinone and codeinone in an acidic aqueous solution. Neopinone ketals, codeinone and neopinone can be converted to codeine.