En oates

SYNTHESIS OF (E)-METHYL 2-CARBOMETHOXY-3,5 -DIPHEN YLPENT-4-EN OATE... 

The Diels-Alder addition of 1-methoxybuta-1,3-diene and methyl but-2-en-oate followed by aromatisation has been described as specific for methyl... 

More recent work ° shows a very specific coordination role for such solvents as dimethylformamide, dimethylacetamide and dimethyl-sulphoxide in the catalysis of hydrogenation reactions by rhodium(III) complexes such as [RhCl3(py)3]. Particularly interesting are the results in (-f) or (—)-l-phenylethylformamide, where through simultaneous coordination to the rhodium with the substrate methyl-3-phenylbut-2-en-oate, the optically active solvent encourages stereospecific hydrogenation to yield (+) or (—)-methyl 3-phenylbutanoate. These results emphasise that further kinetic studies in optically active solvents would be interesting (see p. 717). 

Misoprostil. Also known as Cytotec [59122 6-2] C22H2gO, (a 1 1 mixture of (+/ —) methyl-ll-alpha,16-dihydroxy-16-methyl-9-oxoprost-13E-en-l-oate) (7), this agent is a light yellow liquid that is soluble in water. The methods for preparation are available (8). 

Conversion of androstans to pregnanes via the Reformatsky Reaction 17a-pregn-5-ene-3/3,17/3,21-triol and ethyl 3/3-acetoxy-17/3-hy droxy-17a-pregn-5-en-21-oate, 139... 

Ethoxyacetylene, 74, 136, 138, 181 1 -Ethoxycyclohepta-1,3,5-triene, 365 1-Ethoxycyclohexene, 365 1 - Ethoxy-7,7-dichloronorcarane, 365 17a-Ethoxyethynylandrost-5-ene-3, 17 -diol 3-acetate, 181, 182 Ethoxyethynylmagnesium bromide, 138 21 -Ethoxy-3-methoxy-19-norpregna-1,3,5(10) -trien-20-yne-17 -oI, 139 Ethyl 3 -acetoxy-17/3-hydroxy-17 a-pregn-5-en-21-oate, 139... 

One recent study addressed the response of a parasitoid to the host s spacing pheromone. Aphidius rhopalosiphi did not respond to the spacing pheromone of one host, the cherry-oat aphid Rhopalosiphum padi, which consists of 6-methylhept-5-en-2-one 16,6-methylhept-5-en-2-ol, tridecan-2-one and methyl salicylate. These compounds did not attract or repel the parasitoid. Because the aphid spacing pheromone can potentially be used to cause aphids to disperse, the failure of the parasitoid to respond to the spacing pheromone makes simultaneous use of the spacing pheromone and the parasitoid possible in aphid management [87]. 

It has been shown" that isomerization of the exocyclic allylic system of the five-membered ring D of kaurenols depends on the orientation of the C(15) hydroxyl group. The total synthesis of methyl atis-16-en-19-oate, a tetracyclic diterpenoid possessing a bicyclo[2.2.2]octane skeleton, has been accomplished" using a homoallyl-homoallyl radical rearrangement process of methyl 12-hydroxykaur-16-en-19-oate monothioimid-azolide (280) as the pivotal step. Two plausible mechanisms have been presented" ... 

En me Treatment of LCCs. Purified Bacillus circulans xylanase (specific activity, 110 units/mg protein), purified Coriolus versicolor )9-mannanase (specific activity 179 units/mg protein), purified Thermoascus aurianticum /8-glucosidase (specific activity, 150 units/mg protein), and purified Schizophyllum commune acetyl xylan esterase (AXE specific activity, 180 units/mg protein) were used. Unit activity for xylanase and )9-mannanase was defined as the amount of enzyme catalyzing the release of 1 /xmol reducing power per minute at 50°C and pH 6.0 using oat spelts... 

DilO epidioxyabiet-13-en-18-oate 7a,8a, 13(3,143-Diepoxyabietan-18- Larix kaempferi EBV [126]... 

Edafiogho lO, Alexander MS, Moore JA, Farrar VA, Scott KR (1994) Anticonvulsant enaminones with emphasis on methyl 4-[(p-chlorophenyl)amino]-6-methyl-2-oxocyclo-hex-3-en-l-oate (ADD 196022). Curr Med Chem 1 159-175... 

The asymmetric syntheses of (-)-methyl kaur-16-en-19-oate and (-)-methyl trachyloban-19-oate was achieved by M. lhara and co-workers. One of the last transformations was the deoxygenation of the ketone carbonyl group of the tetracyclic intermediate, which was effected by the Wolff-Kishner reduction. Under the strongly basic conditions the ester functionality was hydrolyzed, so an esterification using diazomethane was necessary as the final step. The major deoxygenated product was (-)-methyl kaur-16-en-19-oate (59%). The minor product was identified as (-)-methyl trachyloban-19-oate (16%). 

Methyl kaur-16-en-19-oate (-)-Methyl trachyloban-19-oate... 

Toyota, M., Wada, T., ihara, M. Totai Syntheses of (-)-Methyi Atis-16-en-19-oate, (-)-Methyi Kaur-16-en-19-oate, and (-)-Methyi Trachyioban-19-oate by a Combination of Paiiadium-Cataiyzed Cycioaikenyiation and Homoaiiyi-Homoaiiyi Radical Rearrangement. J. Org. Chem. 2000, 65, 4565 570. 

A number of partial syntheses have been described in the bicyclic series. The synthesis of methyl (12S)- and (12i )-hydroxylabda-8(17)-en-19-oate utilized the aldehyde (10) as an intermediate. This was obtained from podocarpic acid. The synthesis of the furan methyl lambertianate (11) from dimethyl agathate has been described. Examination of the n.m.r. spectra of the levantenolides (12) has led to a revision of their C-12 stereochemistry. a-Levantenolide has the (12i ) configuration whereas jS-levantenolide has the (125) configuration. The functionalization at C-12 of labdanes by oxidation of C-15 alcohols with iodine and lead tetra-acetate has been described. ... 

Siena. M.G., Cravero, R.M.. de Los Angeles Laborde, M., and Ruveda, E.A., Synthesis of the key intermediate ( )-18,19-dinor-14c(7/-cheilantha-12,15-dien-17-one and its transformation into the geochemical marker 18,19-dinor-13P /,14oc//-cheilanthane and the marine-type sesterterpene methyl scalar-17-en-25-oate, J. Chem. Soc., Perkin Trans. 1, 1227, 1985. 

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