Sclareolide was obtained in high yield (> 96%) in a one pot reaction from sclareol by ozonolysis and treatment in situ by H2O2/NaOH/CH3CO3H. This commercially interesting product gave Ambrox® in very good yield (Total yield from sclareol > 85%) by reduction and subsequent cyclisation of the intermediary bicyclohomofarnesane 8α-12diol.
A. Fekih, F. Habbachi
Ambrox®, sclareol, sclareolide, ozonolysis
The condensation of salycilic aldehyde with m-phenylene diacetonitrile, when catalysed by anion-exchange resins, leads selectively to the corresponding biscoumarin or bisiminocoumarin in high yield. A study of the effects of various physicochemical parameters governing the behaviour of the ion exchanger allowed the most favorable reaction conditions to be determined. The best results were obtained using IRA 900 macropores resin, appropriately hydrated. A reaction mechanism involving ionic intermediates is proposed.
H. Ammar, Y. Le Bigot, R. El Gharbi
Ion-exchange resins, Biscoumarins, Salicylic aldehyde
The hydrazides 1, react with hydrazonates N-1-ethoxycarbonylated 2 to give 1,2,4-triazol-5-ones 3. The X ray crystal structure of one compound has been analysed and confirms the proposed structure. The C17H16N4O2 is monoclinic P21/n with the following unit cell dimensions a = 13.460(6)Å, b = 7.370(2)Å, c = 15.747(6)Å, β = 96.30(2)°, z = 4, ρx = 1.319g.cm-3. The average structure was determinated at R = 0.0622 and Rw = 0.2210. Examination of the structure shows isolated dimers of C34H32N8O4 parallel to the c axis : the molecules are connected through intermolecular hydrogen bonds.
A. Rekik, S. Chaabouni, F. Chabchoub, S. Kamoun, M. Salem
Hydrazonates-triazolones, Crystal structure
The organomagnesiens and allyl zinc bromide react with N-(ethoxycarbonylethyl) imidates to give oxazines in good yields. The process of the reaction is discussed.
M. Kamoun, B. Hajjem, B. Baccar
Extraction and separation of alkaloids from the leaves of Hammada scoparia (Pomel) Iljin have led to the isolation and identification of eight alkaloids : N-methylisosalsoline, carnegine, isosalsoline, N-methylcorydaldine, tryptamine, Nb-methyltiyptamine, 2-methyl -1 ,2,3,4-tetrahydro-β-carboline and leptocladine. The two latter compounds are isolated for the first time from Hammada scoparia.
R. Jarraya, M. Damak
Hammada scoparia, alkaloids, isoquinolines, 2-methy1-1,2,3,4-tetrahydro-β-carboline, leptocladine
The reaction of 2-diazopropane 1 with (E)-disubstituted 3-butene-2-ones 2a-d, at 0°C, gave a 3-acetyl-5,5-dimethyl- Δ1-pyrazolines 3a-d. The photolysis of 3a-d led to the exclusive obtaining of gem-dimethyl cyclopropylketones 4a-d in a stereospecific manner.
J. Lacheb, F. Abdelleoui, M.-T. Martin, A. Khemiss
2-diazopropane, Δ1-pyrazolines, photochemistry, cyclopropane
A convenient preparation of 4-amino-6-ethoxythieno[2,3-b] pyridines is reported. They are prepared by intramolecular cyclization reaction between the corresponding iminoethers derived from 2-amino-3-cyanothiophenes and organomagnesiens.
K. Dridi, M. L. El Efrit, H. Zantour
The condensation of the malonate and the ethyl cyanomalonate with the simple iminoesters 1, N-acylated 2, and N-ethoxycarbonylated 3 in a basic medium leads to potential intermediates in heterocyclic synthesis.
F. Zribi, A. Rekik, F. Chabchoub, M. Trabelsi, M. Salem
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