摘要:
Novel processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important C.sub.5 building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.
摘要:
Novel processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important C.sub.5 building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.
摘要:
A processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important C.sub.5 building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.
摘要:
Novel processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important CS building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.
摘要:
A novel process for the manufacture of a .gamma.-halotiglic aldehyde HalH.sub.2 C-CH.dbd.C(CH.sub.3)-CHO [I], wherein Hal signifies chlorine or bromine, comprises haloalkoxylating a 1-alkoxy-2-methyl-1,3-butadiene H.sub.2 C.dbd.CH-C (CH.sub.3).dbd.CH-OR.sup.1 [II], wherein R.sup.1 signifies C.sub.1-4 -alkyl, using a particular halogenating agent in a C.sub.1-4 -alkanol (R.sup.2 OH) and hydrolyzing the thus-obtained .gamma.-halotiglic aldehyde dialkyl acetal HalH.sub.2 C-CH.dbd.C(CH.sub.3)-CH (OR.sup.1)(OR.sup.2) [III] to the desired .gamma.-chloro- or .gamma.-bromotiglic aldehyde I. The halogenating agent used in this process is selected from an alkali metal hypochlorite, an alkali metal hypobromite, an alkaline earth metal hypochlorite, an alkaline earth metal hypobromite, tert.butyl hypochlorite, N-bromoacetamide, 1.3-dichloro-5,5-dimethylhydantoin and 1,3-dibromo-5,5-dimethylhydantoin. Further aspects of the present invention are the use of the thus manufactured .gamma.-halotiglic aldehyde for the production of .gamma.-acetoxy-tiglic aldehyde or of a Wittig aldehyde halide Hal-Ph.sub.3 P.sup.+ CH.sub.2 -CH.dbd.C(CH.sub.3)-CHO [VII], wherein Hal signifies chlorine or bromine and Ph a process for the catalytic dealkoxylation of the 1,1,3-trialkoxy-2-methyl-butane CH.sub.3 -CH(ORl)-CH(CH.sub.3)-CH(OR.sup.1).sub.2 [VI] to the corresponding 1-alkoxy-2-methyl-1,3-butadiene II in the gas phase using an aluminium silicate of medium specific surface as the catalyst. The products I, .gamma.-acetoxy-tiglic aldehyde and VII are known, important intermediates for the production of various apocarotenoids and diapocarotenoids as well as of Vitamin A.
摘要:
A process for the manufacture of a .gamma.-acetoxy-tiglic aldehyde by reacting a .gamma.-bromotiglic aldehyde or a .gamma.-chlorotiglic aldehyde with sodium acetate or potassium acetate in an organic solvent in the presence of a phase transfer catalyst.
摘要:
A novel process for the manufacture of a .gamma.-halotiglic aldehyde HalH.sub.2 C--CH.dbd.C(CH.sub.3)--CHO �I!, wherein Hal signifies chlorine or bromine, comprises haloalkoxylating a 1-alkoxy-2-methyl-1,3-butadiene H.sub.2 C.dbd.CH--C(CH.sub.3).dbd.CH--OR.sup.1 �II!, wherein R.sup.1 signifies C.sub.1-4 -alkyl, using a particular halogenating agent in a C.sub.1-4 -alkanol (R.sup.2 OH) and hydrolyzing the thus-obtained .gamma.-halotiglic aldehyde dialkyl acetal HalH.sub.2 C--CH.dbd.C(CH.sub.3)--CH(OR.sup.1)(OR.sup.2) �III! to the desired .gamma.-chloro- or .gamma.-bromotiglic aldehyde I. The halogenating agent used in this process is selected from an alkali metal hypochlorite, an alkali metal hypobromite, an alkaline earth metal hypochlorite, an alkaline earth metal hypobromite, tert.butyl hypochlorite, N-bromoacetamide, 1.3-dichloro-5,5-dimethylhydantoin and 1,3-dibromo-5,5-dimethylhydantoin. Further aspects of the present invention are the use of the thus-manufactured .gamma.-halotiglic aldehyde for the production of .gamma.-acetoxy-tiglic aldehyde or of a Wittig aldehyde halide Hal-Ph.sub.3 P.sup.+ CH.sub.2 --CH.dbd.C(CH.sub.3)--CHO �VII!, wherein Hal signifies chlorine or bromine and Ph signifies phenyl, as well as a process for the catalytic dealkoxylation of the 1,1,3-trialkoxy-2-methyl-butane CH.sub.3 --CH(OR.sup.1)--CH(CH.sub.3)--CH(OR.sup.1).sub.2 �VI! to the corresponding 1-alkoxy-2-methyl-1,3-butadiene II in the gas phase using an aluminium silicate of medium specific surface as the catalyst. The products I, .gamma.-acetoxy-tiglic aldehyde and VII are known, important intermediates for the production of various apocarotenoids and diapocarotenoids as well as of Vitamin A.
摘要:
A process for manufacturing a hydroxylated isoflavone of the formula (I) given in the description comprises re-acting an appropriately substituted 2-hydroxydeoxybenzoin of the formula (II), also given in the description, with a formic acid anhydride of the formula HCOOCOR3, wherein R3 signifies C2-20-alkyl or various other groups as given in the description, in presence of a base or in a solvent which acts as a base, and if necessary promoting the ensuing hydrolysis of the so-produced acylated form of the hydroxylated isoflavone of the formula I by acidification. Of particular interest as products of this process are the 5,7dihydroxyisoflavones, e.g. genistein (5,7,4′-trihydroxyisoflavone). Isoflavones display many useful biochemical effects.
摘要:
The claimed invention relates to cyclic dienol ethers of formula (III). wherein R3 is hydrogen and R4 is C1-4 alkoxy or R3 and R4 together form an optionally substituted methylenedioxy group —O—C(R5)(R6)—O—, wherein R5 and R6 are each independently hydrogen, C1-4 alkyl or phenyl.
摘要:
A process for manufacturing a hydroxylated isoflavone of the formula (I) given in the description comprises re-acting an appropriately substituted 2-hydroxydeoxybenzoin of the formula (II), also given in the description, with a formic acid anhydride of the formula HCOOCOR3, wherein R3 signifies C2-20-alkyl or various other groups as given in the description, in presence of a base or in a solvent which acts as a base, and if necessary promoting the ensuing hydrolysis of the so-produced acylated form of the hydroxylated isoflavone of the formula I by acidification. Of particular interest as products of this process are the 5,7dihydroxyisoflavones, e.g. genistein (5,7,4′-trihydroxyisoflavone). Isoflavones display many useful biochemical effects.