Patent GB-887686-A (GB)
Title: Improvement in the production of symmetrically substituted conjugated hexatrienes and their vinylogues
Inventor: STILZ WALTER
IPC: C07C17/26
Filed: 1959-10-01
Abstract: Symmetrically substituted conjugated hexatrienes and their vinylogous compounds are obtained by reacting a bis-phosphonic acid ester of the general formula <FORM:0887686/IV (b)/1> <FORM:0887686/IV (b)/2> in which n is 0, 1 or 2, R is a hydrogen atom, an alkyl, cycloalkyl, aralkyl, or aryl radical and R1 and R2 each represent an alkyl group with a proton acceptor and a carbonyl compound and when a bis-phosphonic acid ester of the second given formula is used subsequently hydrogenating the central carbon-carbon triple linkage to a double linkage.  The carbonyl compound may be a saturated or unsaturated aldehyde or ketone and the following compounds are specified: formaldehyde, acetaldehyde, acetone, methylglyoxal acetal, methoxyacetone, hydroxyacetone (acetol), glyoxylic acid esters, glycol aldehyde and its acetate and ethers, crotonaldehyde, tiglic aldehyde vinyl methyl ketone, sorbic aldehyde, benzaldehyde, cinnamaldehyde, fluorenone, 2,6-dichlorobenzaldehyde Michler's ketone, phenyl pentadienal, 2,6,9-trimethyl-pentadecapentaene-(2,6,8,10,12)-one-(14), 8-(21,61,61-trimethylcyclohexene-(11) -yl-(11)-6-methyloctatriene - 3,5,7-one - (2); 8 - (21,61,61 - trimethyl - cyclohexa diene - (11,31) - yl - (11)) - 6 - methyloctatriene - (3,5,7) - one - 2; 1,1 - dialkoxy - 2 - methyl - heptadiene - (2,4) - one - (6); 8 - (21,61,61 - trimethyl - 4 - acetoxy - cyclohexene - (11) -yl - (11)) - 6 - methyl octatriene - (3,5,7) - one - 2; beta formylcrotonic acid, beta-acetyl acrylic acid, delta-formyl sorbic acid, 3-methyl-7-formyloctatriene - (2,4,6) - acid; 2 - methyl - 5 - acetyl pentadiene - (2,4) - acid; 4 - methyl - 7 - acetyl - heptatriene - (2,4,6) - acid, and the esters of these acids. Suitable proton acceptors are organic and inorganic bases, e.g. alkali metal and alkaline earth metal hydroxides, alcoholates and amides, strongly basic amines and basic ion exchange resins.  The reaction is preferably carried out in a solvent, e.g. an ether, alcohol, or hydrocarbon, water, or a polar organic solvent, e.g. formamide, demethyl-formamide, dimethyl sulphoxide or N-methyl-pyrrolidone. Suitable temperatures are from 0 DEG C. to 100 DEG C. and it is preferable to work in an atmosphere of an inert gas, e.g. nitrogen or argon.  Usually 2 moles of the carbonyl compound are used per mole of the phosphorus compound but an excess of either may be used. Examples are given for the production of (1): 1,14-diphenyl-5,10 - dimethyl - tetradecahexaene-(1,3,5,9,11,13)-ine-(7) which may be partially hydrogenated to form 1,14 - diphenyl - 5,10 - dimethyl - tetradecaheptaene - (1,3,5,7,9,11,13); (2): 1,10 - diphenyl - 3,8 - dimethyl - decatetraene - (1,3,7,9)-ine-(5) and its partially hydrogenated product; (3): 1,4 - bis - carbethoxy - 2,5,10,13 - tetramethyltetradecahexaene - (1,3,5,9,11,13) - ine-(7) and its partly hydrogenated product; (4): 1,6-diphenyl - hexatriene - (1,3,5); (5): 2,7 - dimethyl - octatriene - (2,4,6) - dial - 1,8; (6): di - biphenylene hexatriene; (7): 1,6 - bis (21,61-dichlorophenyl) - hexatriene - 1,3,5; (8): 1,4 - bis - cyclohexylidene - butene - 2; (9): 2,7 - dimethyl - octatriene - (2,4,6) - dial - (1,8); (10): 1,6 - bis - piperonyl - hexatriene; (11): 2,7 - dimethyl - octatriene - (2,4,6) - dial - (1,8); (12): 1,6 - diphenyl hexatriene and (13): 1,10 - diphenyl - 3,8 - dimethyl - decapentaene - (1,3,5,7,9).  The products are useful as intermediates, as pharmaceuticals, and as provitamin-A-active dyestuffs for foods.  The bis-phosphonic acid esters are obtained by reacting a compound of the general formula <FORM:0887686/IV (b)/3> or a 1,11 dehydro derivative thereof with a phosphorus acid ester of the general formula (R3O)(R2O)P(OR1), Y being halogen, e.g. Cl or Br, or the O-tosyl radical <FORM:0887686/IV (b)/4> Examples are given for the preparation of 2,7-dimethyl - octadiene - 2,6 - ine - (4) - diphosphonic acid-(1,8)-tetraethyl ester and butene-2-diphosphonic acid-1,4-tetramethyl, tetraethyl, tetraisopropyl and tetrabutyl esters.  Specifications 693,259, 783,389 and 813,539 are referred to.