Curcumin has been prepared in 80% yield from vanillin and acetylacetone/BaOs in the presence of tri-sec. butyl borate and butylamine. The reaction was carried out in ethyl acetate at room temperature. Eight compounds related to curcumin have also been synthesized.

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The enzyme specificity in the biosynthesis of prostaglandins has been investigated by incubation of a particulate fraction of sheep vesicular glands with w6 tri-and tetraenoic CIS-CZZ fatty acids and isomers of w6 eicosatrienoic acid (20 : 3 06). The chemical synthesis of the various substrate fatty acids is described. The tetraenoic fatty acids were converted into a series of prostaglandin Ez homologues and the trienoic fatty acids into a series of prostaglandin El homologues. The only isomer of 20 : 3 w6 which showed a fairly high conversion into an isoprostaglandin E l was the 0 7 compound. Maximum conversions were obtained from w6 CZO acids.The smooth muscle stimulating activity of prostaglandin EL and Ez appears to be very specific. All other prostaglandins had much lower activities.

Hydrogenation of skipped polyynoic acids and esters over Lindlar's catalyst in the presence of quinoline proceeds with optimum results in light petroleum, ethyl acetate. or acetone at room temperature, yielding the corresponding all-cis polyenoic compounds in purities of 90-99%. depending on the number of triple bonds.For hydrogenations of this type mechanistic schemes are presented. including the formation of ene-ynoic intermediates. Using Langmuir adsorption and Hinshelwood kinetics. analogue computer simulation showed a simultaneous uptake of more than one H, molecule to be an important step in the reaction route.The formation of rrr1n.s-double bonds occurs only uirr isomerization of cisdouble bonds.In our laboratory the relationship between structure, essential fatty acid activity, and rate of conversion into prostaglandins of unsaturated fatty acids and the physiological action of the prostaglandins have been studied extensively (for a review see I ) . For this study. polyenoic acids and esters with 3 to 6 all-cis skipped double bonds had been prepared by cis-hydrogenation of synthesized polyynoic a c i d P 4 .Until now they were synthesized only by reduction in the presence of Lindlar's catalyst and quinoline5, followed by purification via T L C or counter-current distribution. Although &-hydrogenation of skipped