C(C(C)=[O:4])=C.Cl[CH2:7][CH2:8][CH2:9][C:10]#[C:11][CH2:12][CH2:13][C:14](=[O:16])[CH3:15].[C-:17]#[N:18].[Na+:19]>C(O)C>[C:17]([CH2:7][CH2:8][CH2:9][C:10]#[C:11][CH2:12][CH2:13][C:14](=[O:16])[CH3:15])#[N:18].[OH-:4].[Na+:19]The manufacture of the latter novel intermediates is exemplified by the consecutive synthetic steps involving first, reaction of 5-chloropent-1-yne with butyl lithium to form the corresponding lithium acetylide, reaction of that organometallic compound with boron trifluoride or boron trichloride to afford the tri-(5-chloropent-1-ynyl) boron derivative, which is reacted with methyl vinyl ketone to afford 9-chloro-5-nonyn-2-one, reaction of the latter substance with sodium cyanide in aqueous ethanol to yield 9-cyano-5-nonyn-2-one, saponification of that nitrile with aqueous sodium hydroxide in ethanol to produce 9-oxo-5-decynoic acid, followed by reduction of the olefinic double bond, thus affording the 9-oxo-5-decenoic acids. The cis-acid is conveniently produced by catalytic hydrogenation, e.g. with a palladium-on-barium sulfate catalyst in the presence of a catalyst poison such as quinoline, while the trans-acid is obtained by chemical reduction, e.g. with sodium and liquid ammonia.
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