Abstract:
Disclosed is a process for preparing cis-trans isomer mixtures of 2,2-dimethyl-3(.beta.,.beta.-dichlorovinyl)-cyclopropane-1-carboxylic acid esters, having a high cis/trans isomer ratio, wherein a 4,4-dimethyl-5-halogen-6-alkoxytetrahydro-pyrone or a 3,3-dimethyl-4-halogen-5-oxo-pentanic acid ester is reacted with dichlorophosphonic acid esters in the presence of alkali alcoholates or alkali hydrides or lithium alkyls.Also disclosed are novel starting tetrahydropyrone compounds usable in the above process, and a process for preparation of the novel compounds which includes reacting .beta.,.beta.-dimethyl-.gamma.,.delta.-dihalogen-.delta.-valerolactones with alkali alcoholates at reaction temperatures between -10.degree. and +50.degree. C.
Abstract:
A method of preparing certain dihalogen vinyl cyclopropane carboxylic acid esters of the formula ##STR1## wherein R is an alkyl moiety and X is chlorine or bromine by exposing a dihalogen vinyl dihydrofuran of the formula ##STR2## to light, e.g., ultraviolet light. Also disclosed is a method for preparing such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofurans by reaction of a .beta.-alkoxycrotonic acid ester or 3,3-bisalkoxybutyric acid ester with a 1,1,1-trihalogen-4-methyl-3- or -4-pentene-2-ol in the presence of an acid catalyst. Also disclosed is a method of converting such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta., .beta.-dihalogenvinyl)-4,5-dihydrofuran by thermal rearrangement into 2,5,5-trimethyl-3-carbalkoxy-4-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofurans. Such 2,4,4- and 2,5,5-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofurans are new.
Abstract:
A method of preparing certain dihalogen vinyl cyclopropane carboxylic acid esters of the formula ##STR1## wherein R is an alkyl moiety and X is chlorine or bromine by exposing a dihalogen vinyl dihydrofuran of the formula ##STR2## to light, e.g., ultraviolet light. Also disclosed is a method for preparing such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta..beta.-dihalogenvinyl)-4,5-dihydrofurans by reaction of a .beta.-alkoxycrotonic acid ester or 3,3-bisalkoxybutyric acid ester with a 1,1,1-trihalogen-4-methyl-3-or -4-pentene-2-ol in the presence of an acid catalyst. Also disclosed is a method of converting such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofuran by thermal rearrangement into 2,5,5-trimethyl-3-carbalkoxy-4-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofurans. Such 2,4,4- and 2,5,5-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofurans are new.
Abstract:
A method of preparing certain dihalogen vinyl cyclopropane carboxylic acid esters of the formula ##STR1## wherein R is an alkyl moiety and X is chlorine or bromine by exposing a dihalogen vinyl dihydrofuran of the formula to light, e.g., ultraviolet light. Also disclosed is a method for preparing such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogen-vinyl)-4,5-dihydrofurans by reaction of a .beta.-alkoxycrotonic acid ester or 3,3-bisalkoxybutyric acid ester with a 1,1,1-trihalogen-4-methyl-3- or -4-pentene-2-ol in the presence of an acid catalyst. Also disclosed is a method of converting such 2,4,4-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofuran by thermal rearrangement into 2,5,5-trimethyl-3-carbalkoxy-4-(.beta.,.beta.-dihalogen-vinyl)-4,5-dihydrofurans. Such 2,4,4- and 2,5,5-trimethyl-3-carbalkoxy-5-(.beta.,.beta.-dihalogenvinyl)-4,5-dihydrofurans are new.
Abstract:
An air-compressing internal combustion engine with oblique injection into an antechamber having a sphere-like combustion space and conduit of arranged offset relative to one another. A spheroid impact head with a cup shaped recess on the underside thereof facing the conduit is provided in the lower half of the combustion space. A glow plug is arranged in the downward current of the air flow downstream of the injection nozzle in the antechamber.
Abstract:
There are disclosed substituted lactones of the formula ##STR1## wherein A stands for --CH--CH.sub.2 X (X being Cl, Br or OH), --CHY--CHY-- (Y being Cl or Br), or ##STR2## and R.sup.1, R.sup.2 and R.sup.3 are the same or different radicals from the group of hydrogen and C.sub.1 to C.sub.10 alkyls, at least one of the radicals R.sup.1, R.sup.2 and R.sup.3 being such an alkyl radical, and process for making the same.
Abstract:
There are disclosed and claimed substituted cyclic lactones and process for preparation thereof. In particular, there are disclosed substituted cyclic lactones having alkyl substituents on the ring, especially such lactones having substituents on the ring of which two on the same carbon atom.Additionally, the invention herein disclosed and claimed relates to a process for the preparation of lactones by heating a six-membered hydroxy substituted lactone in the presence of a catalyst.
Abstract:
Resorcinols of the structure of p-orsellinic acid ester are obtained from pyrones of the formula ##STR1## by the action of no more than catalytic amounts of bases.
Abstract:
There are disclosed substituted lactones of the formula ##STR1## wherein A stands for --CH--CH.sub.2 X (X being Cl, Br or OH), --CHY--CHY-- (Y being Cl or Br), or ##STR2## and R.sup.1, R.sup.2 and R.sup.3 are the same or different radicals from the group of hydrogen and C.sub.1 to C.sub.10 alkyls, at least one of the radicals R.sup.2, R.sup.2 and R.sup.3 being such an alkyl radical, and process for making the same.
Abstract:
3-alkyl-6-methyl-.beta.-resorcylic acid esters of the Formula ##STR1## wherein R.sup.1 and R.sup.2 represent identical or different alkyl groups of 1 to 10 carbon atoms, are prepared by the reaction of .alpha.-pyrones of the formula ##STR2## wherein R.sup.1 and R.sup.2 have the above meaning, with a base.