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1

Amidation-Sulfonation of Selected Unasaturated Monoterpenes

Wełniak M.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 2

203-210

EN

Amidation-sulfonation of (+)-camphene (1), (-)-_- and (-)-_-pinene (3,4), (+)-limonene (5), (+)-2-carene (16), and (+)-carvone (21) with a mixture of 25% oleum and aceto- or propionitrile is described. Camphene (1) gave racemic exo-2-amidobornanesulfonic acids (8,9), whereas 3 and 4 produced optically active p-mentheneamidosulfonic acids (10-15). Under the same reaction conditions 1,4-addition to (+)-2-carene (16) leading to (1R,4R)-(-)-4-(1-acetylamino-1-methylethyl)-1-methyl-cyclohex-2-enesulfonic acid (17) was observed. Mixtures of diastereomeric structural terpene analogues of N-acetyltaurine were obtained from 5 and 21. Mechanisms of the investigated reactions are proposed.

2

The Reactions of Selected Terpene Alcohols with Acetonitrile in the Presence of Boron Trifluoride Etherate

Wełniak M.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 10

1405-1411

EN

Aseries of thirteen terpene alcohols 1-13 of bornane, fenchane and isotricyclene systems was subjected to the reaction with acetonitrile in the presence of BF3_Et2O as a catalyst to give respective acetamides and/or alkenes. The use of boron trifluoride etherate instead of the usually applied protonic donors let us establish beyond any doubt the carbonium ion stage participation. The assumed reaction course was corroborated by cationic Wagner-Meerwein, Namietkin and homoallylic rearrangements observed during studies under investigation. Simultaneously no evidence for the imidate formation was found. Such a mode of the reaction mechanism was alternatively suggested earlier by Sjöberg [9] for the reaction of sec- and tert-butanol with acetonitrile in the presence of boron trifluoride etherate.

3

Novel Rearrangement of Tertiary Fenchyl Alcohols with Sulfuric Acid in Acetonitrile

Wełniak M.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 1

37-44

EN

The influence of steric hindrance on rearrangements of tertiary 2-fenchyl cations under the Ritter reaction conditions (CH3CN/H2SO4) has been described. Depending on the branching of alkyl substituents at the C-2 position, the reaction time and temperature, different reaction courses have been observed. After 10 minutes at -20 to -15°C alcohol 2 (R = iso-Am) gave alkenes 7, whereas a pair of amides 8 and 9 for 24 hours at ambient temperature as a result of successive exo-3,2-methyl shift,Wagner-Meerwein rearrangement and endo-6,2-hydride shift. Alkene 10 was obtained as a primary product from alcohol 3 (R = iso-Bu) after 10 minutes at -20 to -15°C. When the same reaction was continued for 24 hours at room temperature, amide 12 has been obtained as the only product. It was explained by the operation of endo-6,2-hydride shift after protonation of alkene 10 and further reaction with acetonitrile. In the case of alcohols 4-6 with bulky isopropyl, sec-butyl and 2-sec-amyl substituents, a novel rearrangement to tetrasubstituted alkenes containing the bicyclo[3.1.1]heptane skeleton have been notified. The mechanistic proposals for the investigated reaction are presented.

4

Thiophosphates and Selenophoosphjates as Tools in the Construction of Carbon-Carbon Double Bond

Skowrońska A., Dybowski P., Koprowski M., Krawczyk E., Maciągiewicz I.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 8

1121-1135

EN

Efficient new methodology of regio- and stereoselective synthesis of a variety of functionalized mono- and polycyclic compounds based on thio- and selenophosphates is reported. The representative examples of these compounds are: vinyl thiiranes, conjugated dienes, cycloadducts, _,_-unsaturated carbonyl compounds, allylic alcohols, _-hydroxy ketones and aromatic compounds.

5

The Ritter reaction of terpenes. Part 2. The fenchyl system

Wełniak M.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 6

1021-1027

EN

The Ritter reaction of fenchyl alcohols 2a-f was examined. Surprisingly, in the case of alcohols 2a-d, formation of the corresponding alkenes 3 was observed. These compounds underwent, in turn, Namietkin and Wagner-Meerwein rearrangements, followed by endo-6,2-hydrogen shift to give acetamides 8 and 9, The alcohol 2e gave a mixture of hydrocarbons 11 and 12 as well as an anti acetamide 9e. For secondary ando-2-fenchol (2f) exo-isofenchyl acetamide (15) was the only product as a result of endo-6,2-hydrogen shift and subsequent reaction with acetonitrile.

6

Reaction of benzo[h]naphthyridine N-oxides with phenyl isocyanate

Bachowska B., Zujewska T.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 1

89-92

EN

Benzo[h]naphthyridine N-oxides reacted with phenyl isocyanate in dimethylformamide to give carbamic acid derivative at room temperature or anilino derivatives at 150 degree C. The process proceeded via 1,3-dipolar cycloaddition followed by aromatization with N-O bond cleavage and loss of CO2 at higher temperature.