A PROCESS FOR THE STEREOSELECTIVE REDUCTION OF alpha , beta -UNSATURATED KETONES

Abstract: A process for the preparation of alpha , beta -unsaturated alcohols of general formula (I), wherein R means an alkyl group of 1-4 carbon atoms, or benzoyloxy group optionally substituted with a phenyl group; R<1> means a hydrogen atom or an alkyl group of 1-4 carbon atoms; R<2> means a hydrogen atom or an alkyl group of 1-4 carbon atoms; R<3> means an alkyl group of 1-6 carbon atoms optionally substituted by phenyl group or cycloalkyl group of 5-7 carbon atoms; or a phenoxy group optionally substituted by a halogen atom, or a cycloalkyl group of 5-7 carbon atoms; R<4> means a hydrogen atom or a halogen atom; characterized in that a alpha , beta -unsaturated ketone of general formula (II) wherein the meanings of R, R<1>, R<2>, R<3>, and R<4> are as given above, is diastereoselectively reduced with a borohydride type compound in an aprotic solvent, in the presence of an inorganic substance dissoluble in the reaction mixture and having particle size from 0.01 micrometer to 10000 micrometer and optionally from the resulting mixture of epimeric alpha , beta -unsaturated alcohols of general formula (I) and (III), wherein the meanings of R, R<1>, R<2>, R<3>, and R<4> are as given above, the alpha , beta -unsaturated alcohol of general formula (I) is separated by methods known per se.

Description: A process for the stereoselective reduction of α, β- unsaturated ketones The present invention relates to a new process for the preparation of α, β- unsaturated alcohols of general formula (I) by the diastereoselective reduction of α, β - unsaturated etons of general formula (II) α, β- Unsaturated alcohols of general formula (I) are important key intermediates of prostaglandine derivatives used in veterinary and human medicine The synthesis of these compounds is carried out most frequently by reduction of α, β- unsaturated ketones of general formula (II) , when a mixture of α,β- unsaturated alcohols of general formula (I) and their epimers of general formula (III) is formed These two epimer alcohols are separated directly or during some further steps of chemical transformation, usually by chromatographic procedures The reduction of the keto group of α, β- unsaturated ketones of general formula (II) was studied in detail in order to enhance the yield and ratio of α, β- unsaturated alcohols of general formula (I) and at the same time to avoid saturation of the , β - double bond In the prior art the reduction of α, β- unsaturated ketones of general formula (II) was realized by using borohydπde reagents containing a bulky, possibly optically active substituent and in a solvent having ether character (e g in tetrahydrofurane, or in a mixture of tetrahydrofurane, diethyl -ether and pentane), at a temperature from -78°C to -130°C, where the ratio of , β- unsaturated epimer alcohols of general formula (I) and of general formula (III) is altered between 1 2-4 5 (J Am Chem Soc 95, 1491 (1971), J Am Chem Soc 94, 8616 ( 1972), US- 3,974, 183 HU-PS-175 889 Hungarian Patent ) As reducing agents commercially not available lithium - dπsopinocam - phenyl- tert- butyl- borohydπde, lιthιum-2-thexyl-8- methyl-2-borobιcyclo[3,3, l ]nonyl-borohydπde, lithium tπcyclopentyl-borohvdπde or hthium-diisobutyl- tert- butyl- aluminumhydπde and L-selektπde® (lithium-tπ-sec - butyl-borohydπde) (all containing bulky groups) were used among others Some representatives of α, β- unsaturated ketons of general formula (II) were reduced by applying zinc borohydπde too, in 1 ,2- dimethoxyethane at 0 °C and at room temperature, where the epimers of general formula (I) and general formula (III) were formed m an 1 1 ratio (J Am Chem Soc 91, 5675 ( 1969), J Am Chem Soc 94, 8616 (1972), US-3,970,684, Using sodium borohydπde in ethanol at -30°C or lithium- tπalkyl-borohydπde at a temperature lower than - 90°C as reducing agents, the ratio of the epimeπc α, β- unsaturated alcohols of general formula (I) and of general formula (III) fluctuated between the ratios of 50 50 and 60 40 (J Am Chem Soc 94, 8616 ( 1972), EP-A- 435,443, EP-A-455,448, EP-A-467,564, J Med Chem 24, 1353 ( 198 ! ) Using sodium borohydπde as reducing agent the selectivity of the reduction could be increased when the reduction was carried out at - 78°C in methanol or in a mixture of methanol and dichloromethane, in the presence of cerium (III) chloride (EP-A- 219,580, US-4, 739,078) Using borane as the reducing agent in the presence of 5- 10 % air and humidity sensitive oxazaborolydines, a far more favourable diastereomer ratio could be achieved (J Am Chem Soc 109, 7925 ( 1987)), but this method can not be applied on a larger scale Using dnsobutyl-alumιnum-(2,6-dι- tert butyl-4-methyl phenoxide) (J Org Chem 44, 1363 ( 1979), Bull Chem Soc Japan 54, 3033 ( 1981 )) at - 78°C, aluminium- isopropoxide in nitrogen atmosphere and in hot toluene (Synthetic Communications 4, 2 1 1 ( 1974)), dι(ιsobornyloxy)- aluminium-isopropoxide or other modified thium-aluminium-hydπdes (J Am Chem Soc 106, 6717 (1984), Synthetic Communications 9, 799 ( 1979), Synthetic Communications 9, 483 ( 1979)) did not represent any advantage either because of difficulties of preparing these reagents, their sensitivity, and/or the costs of preparing them Under the conditions of catalytic hydrogenation, e g using charcoal containing palladium catalyst of 5 % metal content, the carbon-carbon double bond of the α, β- unsaturated ketons of general formula (II) saturates without the reduction of the ketone group (EP-A-289,349, Synthetic Communications 19, 245 (1989), EP-A- 435,443 It is the object of this invention to provide an industrially feasible process, which is suitable at room temperature and without applying special additives, extreme conditions and reagents for the preparation of compounds of general formula (I) by diastereomeric reduction of ketones of general formula (II) in higher yields them in any known processes The base of this new process achieving this object is the unexpected finding that α, β- unsaturated alcohols of general formula (I) - wherein means an alkyl group containing 1-4 carbon atoms, or in a given case benzoyl group substituted with phenyl group, R' means hydrogen atom or an alkyl group containing 1-4 carbon atoms, R- means hydrogen atom or alkyl group containing 1 -4 carbon atoms, R3 means in a given case an alkyl group containing 1 -6 carbon atoms substituted with phenyl group or with cycloalkyl group containing 5-7 carbon atoms, or in a given case phenoxy group substituted with halogen atom or a cycloalkyl group containing 5-7 carbon atoms, R 4 means hydrogen atom or halogen atom - are formed diastereoselectively upon reduction of α, β- unsaturated ketones of general formula (II) - wherein the meanings of R, R^R^R 3 , and R 4 are as given above - if alkali borohydπdes of small space demand are applied and the reaction is carried out in a heterogen phase, in an aprotic solvent in the presence of inorganic substances which are dissoluble in the reaction mixture and their particle sizes are small According to our experiences within the conditions described above and within the temperature range of -10°C and + 30°C diastereoselectivity barely fluctuated Thus the reaction can be carried out at about the room temperature The term of inorganic substances dissoluble in the reaction mixture and having small particle sizes means farourably silicium compounds and/or aluminium compounds or mixtures thereof These are preferably the silica gels, different types of aluminium oxide, in the first place the "active" aluminium oxides which can be acidic, basic, or neutral in their reaction, the adsorptive capacity of which can be determined by the Brockmann scale / Romp Chemical Encyclopedia Vol I p 1 16- 1 17 (Mύszaki Konvvkιado=Technιcal Publishing House, Bp 1982)/ The term of silica gels which are useful in the claimed new process means silicic acid gels as defined in Romp Chemical Encyclopedia Vol II P 977-978 / Muszaki Konyvkradό, Budapest 1982/ These are for example Silica gel 60, Silica gel G "Small particle sizes" means 0 01- 10000 micrometer preferably the particle size range is from 1 μm to 1000 μm Applicable aprotic solvents preferably halogenated hydrocarbons as chlorobenzene, methylene chloride, carbon tetrachloride, chloroform, 1 , 1,2,2- tetrachloroctane, alkane carboxylic acid esters as ethyl acetate, methyl acetate, methyl propionate, hydrocarbons as xylene, or toluene, alkyl nitriles as acetonitrile, ethers as tetrahydrofurane or diethyl-ether can be used If we use ethanol as solvent for the reduction, or we carry out the reduction without the presence of silica gel, then diasteroeselectivity decreases substantially . The presence of small quantity of alcohol of short carbon chain e g methanol however facilitates the reaction As borohydπdes of small space demand can be applied preferably their commercially available representatives sodιum[tπmethoxy-borohydπde], lithium borohydπde, sodium borohydπde, potassium borohydπde or sodium cyano borohydπde, all of which can be used in solid or powdered form, or their aqueous or methanohc solution After filtering out the insoluble inorganic substance(s) particles from the reaction mixture eraporation of the filtrate a mixture of epimeπc alcohols having general formula (III) and (I) - wherein the meanings of R, R 1 , R-, R-\ and R are as given above - is obtained From this mixture the desired α, β- unsaturated alcohol of general formula (I) can be isolated by applying the known separation methods for example by chromatography on a silica gel column If desired the isolated isolated α, β- unsaturated alcohol of general formula (I) can be further purified by crystallization The following examples are intended to provide those of ordinary skill in the art with a complete disclosure and description of how to conduct the present synthetic process, and are not intended to limit the scope of this invention EXAMPLES Example 1 To 10 ml of an an hydrous solution prepared by dissolving 1 130 mg of ( l S,5R,6R,7R)-6-[(E)-2-bromo-5-cyclohexyl-3-oxo- l-pentenyl]-7-(4-phenyl- benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3- one in chloroform 1,5 g silica gel with particle size 63-200 μm / Silicagel 60, Merck Cat No 107734/ was added During rigorous stirring of the obtained mixture at 19 - 20 °C the solution prepared by dissolving 1 14 mg of sodium borohydπde in 0,22 ml of water was added and stirring was continued intensively for further 60 minutes The reaction mixture was cooled below 0°C, and the excess reducing agent was reacted with 1 ,5 ml 2N hydrochloric acid solution After stirring for 5 minutes 2 ml methanol was added to the mixture and after stirring for further 5 minutes the silica gel was filtered out Silicagel was washed twice in succession with 3 ml chloroform-methanol mixture of 5 1 volume ratio The filtrate was flusted with ethyl acetate into a 25 ml volumetric flask and this flask was filled up to the mark with ethyl acetate The proportion of the produced epimer alcohols, the (lS,5R,6R,7R)-6-[(E)-2-bromo-5-cyclohexvl-3(S)-hvdroxy-l-pentenyl]- 7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0] octane-3- one and the 3(R)- hydroxy epimer is 83 17 as determined by HPLC ( Nova-Pac Silica 4 μm, 150x3,9 cm column, mobile phase n-hexane and ethanol in 94 6 volume ratio) After evaporation of above solution, the main product the 3(S)-hydroxy epimer was obtained with 75 % yield, by isolating it in a column filled with silica gel, and applying a mixture of toluene and ethyl acetate as mobil phase The obtained crystalline substance melted at 127- 129 °C, crystallized from the mixture of toluene and n-hexane Analysis on the base of molecular formula C3 ιH35BrOs, Calculated C 76,20 %, H 7,43 %, Found C 75,96 %, H 7,44 % Example 2 The process was earned out analogously to Example 1 but as starting α, β- unsaturated keton ( l S,5R,6R,7R)-6-[(E)-5-cyclohexyl-3-oxo- l-pentenyl]-7-(4- phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one was applied The proportion of the produced epimeπc alcohols, (l S,5R,6R,7R)-6-[(E)-5-cyclohexyl-3(S)-hydroxy- l- pentenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3- one and the 3(R)- hydroxy epimer was 77 23 and from the mixture the 3(S)-hydroxy epimer was obtained in 72 % yield using column chromatography Analysis on the base of molecular formula C31 H36O5, Calculated C 76,20 %, H 7,43 %, Found C 75,96 %, H 7,44 % Example 3 The process was carried out analogously to Example 1 but as starting α, β- unsaturated keton ( lS,5R,6R,7R)-6-[(E)-4-cyclohexyl-3-oxo-l-butenyl]-7-(4-phenyl- benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one was applied The ratio of the formed epimenc alcohols, the ( l S,5R,6R,7R)-6-[(E)-4-cyclohexyl-3(S)-hydroxy-l-butenyl]- 7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one and its 3(R)- hydroxy epimer was 75 25 The main component which was obtained in 73 % yield was prepared by chromatography using a column filled with silica gel The obtained crystalline substance melted at 92-94°C, crystallized from a mixture of ethyl acetate, dnsopropyl ether and n- hexane Analysis on the base of molecular formula C30H34O5, Calculated C 75,92 %, H 7,22 %, Found C 76, 14 %, H 7, 19 % Example 4 The process was carried out analogously to Example 1 but as the starting α, β- unsaturated keton (l S,5R,6R,7R)-6-[(E)-4-cyclopentyl-3-oxo-l-butenyl]-7-(4- phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one was applied The ratio or the formed epimenc alcohols, the (lS,5R,6R,7R)-6-[(E)-4-cyclopentyl-3(S)-hydroxy-l- butenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one and its 3(R)- hydroxy epimer was 76 24 The main component which was obtained in 71 % yield was prepared by chromatography using a column filled with silica gel Analysis on the base of molecular formula C29H32O5, Calculated C 75,63 %, H 7,00 %, Found C 75,81 %, H 6,88 % Example 5 The process was carried out analogously to Examle 1 but (l S,5R,6R,7R)-6-[(E)-4- phenoxy-3-oxo- 1 -butenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one was applied as starting matenal The ratio of the formed epimenc alcohols, the (l S,5R,6R,7R)-6-[(E)-4-phenoxy-3(S)-hydroxy-l-butenyl]-7-(4-phenyl-benzoyloxy)- 2-oxabιcyclo[3 3 0]octane-3-one and its 3(R)- hydroxy epimer was 6 ! 39 The main component which was obtained in 58 % yield was prepared by chromatography using a column filled with silica gel The obtained crystalline substance melted at 13 1 - 1 32 °C crystallized from the mixture of ethyl acetate, dnsopropylether and n-hexane Analysis on the base of molecular formula C30H28O6, Calculated C 74,36 %, H 5,82 %, Found C 74, 18 %, H 5,91 % Example 6 The process was carried out analogously to Example 1 but ( l S,5R,6R,7R)-6-[(E)-4- ( w-chloro-phenoxy)-3-oxo- 1 -butenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0] octane-3-one was applied as starting material The ratio of the formed epimenc alcohols, the ( l S,5R,6R,7R)-6-[(E)-4- (m-chloro-phenoxy)-3(S)-hydroxy- l-butenyl]- 7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one and its 3(R)- hydroxy epimer was 58 42 The main component which was obtained in 56 % yield was prepared by chromatography using a column filled with silica gel The obtained crystalline substance melted at 105 - 108 °C crystallized from the mixture of ethyl acetate and dnsopropylether Analysis on the base of molecular formula C30H27CIO6, Calculated C 69,43 %, H 5,24 %, Cl 6,83 % Found C 69,62 %, H 5,20 % Cl 6,91 % Example 7 The process was carried out analogously to Example 1 but ( l S,5R,6R,7R)-6-[(E)-5- phenyl-3-oxo- l-pentenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcvclo[3 3 0]octane-3-one was applied as starting material The ratio of the formed epimenc alcohols, the ( l S,5R,6R,7R)-6-[(E)-5-phenyl-3(S)- hydroxy- l-penteny!]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one and its 3(R)- hydroxy epimer was 76 24 The main component which was obtained in 69 % yield was prepared by chromatography using a column filled with silica gel The obtained crystalline substance melted at 13 1 - 132 °C crystallized from the mixture of ethyl acetate and dnsopropylether Analysis on the base of molecular formula C31H30O5, Calculated C 77, 16 %; H 6,27 %, Found C 76,94 %, H 6,27 % Example 8 The process was carried out analogously to Example I but (lS,5R,6R,7R)-6-[(E)-4,4- dιmethyl-3-oxo- 1 -octenyl]-7-(4-phenyl-benzoyloxy)-2-oxabtcyclo[3 3 0]octane-3-one was used as starting mateπal The ratio of the formed epimenc alcohols, the ( l S,5R,6R,7R)-6-[(E)-4,4-dιmethyl-3(S)-hydroxy- l-octenyl]-7-(4-phenyl- benzoy!oxy)-2-oxabιcyclo[3 3 0]octane-3-one and its 3(R)- hydroxy epimer was 79 21 The main component which was obtained in 70 % yield was prepared by chromatography using a column filled with silica gel The obtained crystalline substance melted at 1 13 - 1 14 °C crystallized from the mixture of dnsopropylether and n-hexane Analysis on the base of molecular formula 0H36O5, Calculated C 75,60 %, H 7,61 %, Found C 75,75 %, H 7,49 % Example 9 The process was carried out analogously to Example 1 but ( lS,5R,6R,7R)-6-[(E)-4,4- dιmethyl-3-oxo-l-octenyl]-7-methyl-2-oxabιcyclo[3 3 0]octane-3-one was applied as staπing material The ratio of the formed epimenc alcohols, the ( l S,5R,6R,7R)-6- [(E)-4,4-dιmethyl-3(S)-hydroxy-l-octenyl]-7-methyl-2-oxabιcyclo[3 3 0]octane-3- one and its 3(R)- hydroxy epimer was 80 20 The main component which was obtained in 79 % yield was prepared by chromatography using a column filled with silica gel Analysis on the base of molecular formula C 18H30O3, Calculated C 73,43 %, H 10,27 %, Found C 73,39 %, H 10,32 % Example 10 The process was carried out analogously to Example 1 but ( l S,5R,6R,7R)-6-[(E)-3- oxo-l-octenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3-one was used as starting material The ratio of the formed epimenc alcohols, the ( l S,5R,6R,7R)-6- [(E)-3(S)-hydroxy-l-octenyl]-7-(4-phenyl-benzoyloxy)-2-oxabιcyclo[3 3 0]octane-3- one and its 3(R)- hydroxy epimer is 74 26 The main component which was obtained in 68 % yield was prepared by chromatography using a column filled with silica gel The obtained crystalline substance melted at 64-67 °C crystallized from the mixture of dnsopropylether and n-hexane Analysis on the base of molecular formula C28H32O5, Calculated C 74,98 %, H 7,19 %, Found C 75,21 %, H 7,43 % Example 11 The process was carried out analogously to Example 10 but solid lithium borohydnde was used instead of aqueous sodium borohydπde solution as reducing agent The ratio of the formed epimenc alcohols was 60 40 % The main component ( 1 S,5R,6R,7R)-6-[(E)-3(S)-hydroxy-l-octenyl]-7-(4-phenyl-benzovloxy)-2- oxabιcyclo[3 3 0]octane-3-one was prepared by column chromatography The thus obtained product did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 12 The process was carried out analogously to Example 10 but solid potassium borohydnde was used as reducing agent instead of sodium borohydnde solution, a 72 28 ratio mixture of aqueous 3(S)- and 3(R) epimenc alcohols was obtained, from which the epimenc 3(S)- alcohol was prepared by chromatography The thus obtained product did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to examples 10 or 1 1 Example 13 The process was carried out analogously to Example 1 1 but sodium tπmethoxyboro- hydπde was used instead of lithium borohydnde, a 67 33 ratio mixture of epimenc 3(S)- and 3(R) alcohols was obtained, from which the mam product was prepared by chromatography The thus obtained product did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 14 The process was carried out analogously to Example 10 but carbon tetrachloπde was used as solvent instead of chloroform, a 75 25 ratio mixture of epimenc alcohols was obtained, from which the main product, (lS,5R,6R,7R)-6-[(E)-3(S)-hydroxy-l- octenyl]-7-(4-phenyl-benzoyloxy)- 2-oxabιcyclo[3 3 0]octane-3-one - produced with 40 % yield- was prepared by column chromatography The thus obtained product did not show any decrease of melting point when mixed in discretional ratio with the product prepared according to example 10 Example 15 The process was carried out analogously to Example 14 but toluene was used as solvent instead of carbon tetrachloride, a 74 26 ratio mixture of epimenc alcohols was obtained, from which the 3(S)- alcohol - produced with 57 % yield - was prepared by column chromatography The thus obtained product did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 16 The process was carried out analogously to Example 14 but methylene chloride was used as solvent, a 73 28 ratio mixture of epimenc 3(S)- and 3(R) alcohols was obtained, from which the 3(S)- alcohol -produced with 63 % yield - was prepared by column chromatography Example 17 The process was carried out analogously to Example 14 but acetonitrile was used as solvent, a 60 40 ratio mixture of epimenc 3(S)- and 3(R) alcohols was obtained, from which the 3(S)- alcohol -produced with 48 % yield - was prepared by column chromatography processing Example 18 The process was carried out analogously to Example 14 but tetrahydrofurane was used as solvent, a 61 39 ratio mixture of epimenc 3(S)- and 3(R) alcohols was obtained, from which the 3(S)- alcohol -produced with 45 % yield - was prepared by column chromatography Example 19 The process was carried out analogously to Example 14 but ethyl acetate was used as solvent, a 70 30 ratio mixture of epimenc 3(S)- and 3(R) alcohols was obtained, from which the 3(S)- alcohol -produced with 53 % yield - was prepared by column chromatography Neither of the products prepared according to examples 16 , 17 , 18 , and 19 showed any decrease of melting point when they were mixed in discretional ratio with the product prepared according to example 10 Example 20 The process was earned out analogously to Example 10 but silica gel of 40 - 63 μm particle size /"Silicagel 60" Merck Cat No 109385/ was used From the formed mixture of epimenc 3(S)- and 3(R) alcohols (ratio was 62 26) the main product was obtained by chromatography It did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 21 The process was carried out analogously to Example 10 but silica gel of 5 - 40 μm particle size / " Silicagel G" Merck Cat No 107731/ was used From the formed mixture of epimenc 3(S)- and 3(R) alcohols (ratio 62 26) the main product was obtained by chromatography It did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 22 The process was carried out analogously to Example 10 but Brockmann I acidic aluminium oxide/ Aldrich Cat No 19996-6/ was used instead of silica gel From the formed mixture of epimenc 3(S)- and 3(R) alcohols (ratio was 33 13 ) the main product was obtained by chromatography It did not show anv decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 23 The process was carried out analogously to Example 10 but Brockmann I basic aluminium oxide/ Aldrich Cat No 19944-3/ was used instead of silica gel From the formed mixture of epimenc 3(S)- and 3(R) alcohols (ratio was 2 1) obtain the main product by chromatography It did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10 Example 24 The process was carried out analogously to Example 10 but Brockmann I neutral aluminium oxide/ Aldrich Cat No 19997-4/ was used instead of silica gel From the formed mixture of epimenc 3(S)- and 3(R) alcohols (ratio was 2 5 1 4) obtain the main product by chromatography It did not show any decrease of melting point when it was mixed in discretional ratio with the product prepared according to example 10

Claims: Claims 1. A process for the preparation of α, β- unsaturated alcohols of general formula (I), - wherein R means an alkyl group of 1-4 carbon atoms, or benzoyloxy group optionally substituted with a phenyl group, R ' means a hydrogen atom or an alkyl group of 1-4 carbon atoms, R- means a hydrogen atom or an alkyl group of 1-4 carbon atoms, R J means an alkyl group of 1-6 carbon atoms optionally substituted by phenyl group or cycloalkyl group of 5 -7 carbon atoms, or a phenoxy group optionally substituted by a halogen atom, or a cycloalkyl group of 5 -7 carbon atoms, R4 means a hydrogen atom or a halogen atom - characterized in that a α, β- unsaturated ketones of general formula (II) - wherein the meanings of R, R^, R-, R 3 , and R 4 are as given above - is diastereoselectively reduced with a borohydπde type compound in an aprotic solvent, in the presence of an inorganic substance dissoluble in the reaction mixture and having particle size from 0 01 micrometer to 10000 micrometer and optionally from the resulting mixture of epimenc α, β-unsaturated alcohols of general formula (I) and (III) - wherein the meanings of R, R , R-^, R 3 , and R 4 are as given above - the α, β-unsaturated alcohol of general formula (I) is separated by methods known per se 2. A process according to claim 1 characterized in that a halogenated hydrocarbon is used as aprotic solvent 3. A process according to claim 2 characterized in that carbon tetrachloride, chloroform, or methylenechlonde are used as halogenated hydrocarbon 4 A process according to claim 1 characterized in that an aliphatic carboxylic acid ester is used as an aprotic solvent 5 A process according to claim 4 characterized in that ethyl acetate is used as aliphatic carboxylic acid ester 6. A process according to claim 1 characterized in that an ether-type solvent is used as an aprotic solvent 7. A process according to claim 6 characterized in that tetrahydrofurane is used as an aprotic, ether-type solvent 8. A process according to claim 1 characterized in that a hydrocarbon is used as an aprotic solvent 9. A process according to claim 8 characterized in that toluene or xylene as a hydrocarbon 10. A process according to claim 1 characterized in that an alkylnitπle is used as an aprotic solvent 11. A process according to claim 10 characterized m that acetonitrile is used as alkylnitπle 12 A process according to claim 1 characterized in that methanol or ethanol are used as a cosolvent containing short carbon chain 13 A process according to claim 1 characterized in that an alkali- tπalkoxy- borohydπde is used as borohydnde type compound 14. A process according to claim 1 characterized in that sodιum-[tπmethoxy- borohydnde] is used as alkali- tπalkoxy- borohydπde 15. A process according to claim 1 characterized in that an alkali borohydnde is used as a borohydnde type compound 16. A process according to claim 15 characterized in that lithium borohydπde, sodium borohydπde, or potassium borohydnde are used as alkali borohydπde 17. A process according to claim 1 a silica gel or aluminium oxide as are used an inorganic substance dissoluble in the reaction mixture and having particle size, from 0 01 micrometer to 10000 micrometer 18. A process according to claim 1 characterized in that a silica gel having particle size from 1 μm to 1000 μm is used 19. A process according to claim 1 characterized in that an activated, acidic, basic, or neutral aluminium oxide is used as an in organic substance

Inventors: BALOGHNE KARDOS ZSUZSANNA, BENNO NANDOR, BERESNE POVARNY MAGDOLNA, DALMADI GYULA, EBINGER KATALIN, FORRO LASZLO, GALAMBOS GEZA DI, HAJDU FELIX, HERMECZ ISTVAN, LUKACS GEZA, MOZSOLITS KAROLY, POLIKNE SZIGETI KATALIN, SEBESTYEN JUDIT, SZABO TIBOR, SZEVERENYI ZOLTAN, VAJDA ERVIN, VANKAI GABOR, VOFELY PAL, BALOGHNE, KARDOS, ZSUZSANNA, BENNO, NANDOR, BERESNE, POVARNY, MAGDOLNA, DALMADI, GYULA, EBINGER, KATALIN, FORRO, LASZLO, GALAMBOS, GEZA +DI, HAJDU, FELIX, HERMECZ, ISTVAN, LUKACS, GEZA, MOZSOLITS, KAROLY, POLIKNE, SZIGETI, KATALIN, SEBESTYEN, JUDIT, SZABO, TIBOR, SZEVERENYI, ZOLTAN, VAJDA, ERVIN, VANKAI, GABOR, VOFELY, PAL
Applicants: BALOGHNE KARDOS ZSUZSANNA, BENNO NANDOR, BERESNE POVARNY MAGDOLNA, CHINOIN GYOGYSZER ES VEGYESZET, DALMADI GYULA, EBINGER KATALIN, FORRO LASZLO, GALAMBOS ATTILA & HM, GALAMBOS EVA & HF, HAJDU FELIX, HERMECZ ISTVAN, LUKACS GEZA, MOZSOLITS KAROLY, POLIKNE SZIGETI KATALIN, SEBESTYEN JUDIT, SZABO TIBOR, SZEVERENYI ZOLTAN, VAJDA ERVIN, VANKAI GABOR, VOFELY PAL, BALOGHNE, KARDOS, ZSUZSANNA, BENNO, NANDOR, BERESNE, POVARNY, MAGDOLNA, CHINOIN, GYOGYSZER ES VEGYESZETI, DALMADI, GYULA, EBINGER, KATALIN, FORRO, LASZLO, GALAMBOS, ATTILA +HM, GALAMBOS, EVA +HF, HAJDU, FELIX, HERMECZ, ISTVAN, LUKACS, GEZA, MOZSOLITS, KAROLY, POLIKNE, SZIGETI, KATALIN, SEBESTYEN, JUDIT, SZABO, TIBOR, SZEVERENYI, ZOLTAN, VAJDA, ERVIN, VANKAI, GABOR, VOFELY, PAL
Application year: 1996
Main classification: C07D307
IPC codes: C07D307