GB786349A - Novel unsaturated alcohols and a process for the manufacture thereof - Google Patents

Abstract

The invention comprises both the dienic tertiary alcohols of the general formula <FORM:0786349/IV (b)/1> wherein R1 represents a C2-5 alkyl radical and R2 the methyl radical or R1 and R2 together represent the penta methylene radical, and the corresponding mono-olefinic alcohols wherein the above group >C=CH- in the 6, 7 position is replaced by the group >CH-CH2-. Both classes of alcohols may be prepared by condensing a metal salt of acetylene with either an unsaturated ketone of the general formula <FORM:0786349/IV (b)/2> or the corresponding saturated ketone, hydrolysing the resulting acetylenic alcoholate and catalytically hydrogenating the liberated acetylenic carbinol at the triple bond in the presence of a catalyst which selectively catalyses the reduction of a triple bond to a double bond, e.g. a lead-inhibited palladium catalyst. The products may be used in the preparation of oderiferous compositions and perfumes. In examples: (1) 6-methyl-octen-(5)-one-(2) dissolved in diethyl ether is reacted with sodium acetylide in liquid ammonia; the resulting 3,7-dimethyl-nonen - (6) - yn - (1) - ol - (3) is isolated and catalytically hydrogenated to give 3,7-dimethyl-nonadien - (1,6) - ol - (3); likewise (2) 5-cyclohexylidene - pentanone - 2 is converted to 6-cyclohexylidene - (3) - methyl - hexyn - (1) - ol - (3) which is hydrogenated to 6-cyclohexylidene-3 - methyl - hexen - (1) - ol - (3); (3) 6,8 - di - methyl-nonen (5) one (2) is converted to 3,7,9-trimethyl - decen - (6) - yn - (1) - ol - (3) which is hydrogenated to 3,7,9-trimethyl-decadien-(1, 6)-ol - (3); (4) 6,8 - dimethyl - nonanone - (2), obtained by catalytic hydrogenation of the corresponding nonenone, is converted into 3,7,9-trimethyldecyn-(1)-ol-(3) which is hydrogenated to 3,7,9-trimethyl decen-(1)-ol-(3) and (5) 6-methyl octanone-(2) is converted to 3,7-dimethyl-nonyn-(1)-ol-(3) which is hydrogenated to 3,7-dimethyl nonen-(1)-ol-(3). 5-Cyclohexylpentanone-(2) is also specified as a ketonic reagent. The ketonic starting materials may be prepared by reacting an alcohol <FORM:0786349/IV (b)/3> with an inorganic halogenating agent, condensing the resulting substituted primary allyl halide with an alkali-metal salt of an acetoacetic ester and saponifying and decarboxylating the resulting product and then catalytically hydrogenating when the saturated ketones are required, in which connection reference is made to Specification 785,086.