Acta Chim. Slov. 2003, 50, 419-429. 419 REACTION OF l-PHENYLCYCLOOCTENE WITH NBS. SYNTHESIS OF ALLYLIC ALCOHOLS AND 1,3-DIENES Biilent Biiyiikkidan,* i. Gökay Budak, and Mustafa Ceylan Department of Chemistry, Faculty of Science, Gaziosmanpasa University, 60240, Tokat, Turkey Fax: +90-3562521585, E-mail: bbuyuk@gop.edu.tr Received 21-01-2003 Abstract Reaction of l-phenylcyclooctene (3) with NBS resulted in the formation of a mixture of products (4-8). After column chromatography, we isolated the vinyl bromide 14 and 1,3-dienes 9, 10, bromo-1, 3-dienes 11, 12 and allylic alcohol 15. Reaction of the mixture (4-8) with AgC104 afforded compounds 9, 14, 15 and et;/?-unsaturated ketones 21 and 22. Introduction The unique symmetry of eight-membered rings and their intriguing conformational properties have attracted much theoritecal interest over years. The synthesis of compounds containing ring of this size has been a long-standing problem because of difficulties stemming from the high degree of ring strain and transannular interactions. In recent years, interest has grown considerably in the synthesis of eight-membered rings. " In addition, the discovery of more than 100 cyclooctanoid-based sesqui-, di-, and sesterterpenes have spurred extensive activity in the total svnthesis of this class of natural products. However, neither of these endeavours have provided the occasion for scrutinizing the degree to which an eight-membered ring can be functionalized without postering one or another umvanted transannular process. Paquette has reported that the derivation of cyclooctene gave the polvbrominated products. In the present work, we investigated the reaction of l-phenylcyclooctene (3) with NBS. Results and discussion In the present work we investigated the reaction of l-phenylcyclooctene (3) with iV-bromosuccunimide (NBS). Compound 3 was synthesized by the procedure described in literature. We used cyclooctanone (1) as a starting material. The reaction of 3 with B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. 420 Acta Chim. Slov. 2003, 50, 419-429. phenylmagnesium bromide was followed by dehydration with 4-toluenesulfonic acid (p-TsOH) resulted in cycloocten-l-ylbenzene (3) in good yield (Eq. 1). o PU^U Ph PhMgBr / \, p-TsOH r=\ >- (Eq. 1) THF, 0 °C \ / Benzene, reflux The reaction of 3 with 1 equivalent of NBS was carried out in CCI4 at 65 °C. Examination of the reaction mixture by H NMR spectroscopy revealed that many different compounds were indeed present in the reaction mixture. We determined that the five compounds were the allylic bromides 4-8, which are expected compounds, shown in Figure 1. Confirmation of the proposed structure for compounds 4-8 comes from the C NMR study of the products (C-Br Shifts: ? 62.84, 62.50, 55.79, 51.22, 50.51 ppm). Additionally, from the proton NMR studies it was determined that the compounds 4 and 5 were the main products. Purification of the reaction mixture by column chromatography on silica gel did not lead to the isolation of these compounds. Ph ^Br Ph Ph^ /Br ph Br ^B{ Ph v \ / \^-Br /\ Br 45 6 7 8 Figure 1 Instead, after repeated column chromatography, we isolated compounds 9-13 and 15. These products were presumably formed from compounds 4-8 on silica gel during the chromatographic seperation (Scheme 1). The compounds 4-8 are moisture and heat sensitive and easily liberate bromine atom, and convert into the corresponding alcohols 15 and alkenes 9-12 on column material. In addition, the alkenes 9-12 can also be formed in the reaction medium. In Scheme 1 we also indicated that small amounts of saturated dibromide 14 were formed. The structure of 14 was elucidated from the NMR spectra and it was not isolated in a pure form since during the chromatographic separation 14 eluted together with the unreacted 3. 1 2 3 B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. Acta Chim. Slov. 2003, 50, 419-429. 421 Ph // NS Ph NBS, CCI4, reflux, silicagel Ph Ph Br // NS Ph Br 9, 18% 10, 10% 11, 10% 12, 8% Ph Br ph Br Br ph OH 13, 16% 14, 1% 15, 9% other products 8% Scheme 1 The structures of the isolated products (9-13, 15) have been elucidated on the basis of NMR data and the chemical transformations. IR analysis showed that a hydroxyl group was incorporated into compound 15. Therefore, we assume that this product was formed by a partial hydrolysis of compound 4. Compound 4 contains allylic bromine atom which can be easily hydrolized on column material to the corresponding alcohol 15 (Scheme 2). Similar rearrangements have been reported in the literature. Alcohol 15 was distinguished easily. The proton NMR spectrum of 15 showed the olefinic proton at 8 5.63 ppm, which arises as a triplet (J = 8.5 Hz) and a proton (HC-OH) at 8 4.85 ppm as a doublet of doublet (J = 4.93 and 11.19 Hz). Additionally, the carbon NMR spectrum of 15 showed 12 resonances (C-OH shift: 70.45 ppm). Ali these findings are in good agreement with the structure of 15. Additionally, two products were obtained in 8% yield, which can not be identified clearly. We speculated that these products may be similar to l-hydroxy-3-phenylcycloocta-2-ene according to the NMR studies ( C Shifts:(C-OH), 8 77.03 and 75.83)). 3 B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. 422 Acta Chim. Slov. 2003, 50, 419-429. Ph, Br Ph Ph // NS -HBr Ph -HBr Br Ph, Si02 // Br Ph -HBr 5 10 Scheme 2 OH 15 2-Phenyl-l,3-cyclooctadiene (9) was one of the major products. The formation of 9 can be explained by the elimination of HBr from the allylic bromides 4 and 6 in the reaction medium or during the chromatography. The other 1,3-diene 10 can be formed from 5 in a similar way (Scheme 2). The structures of 9 and 10 were determined on the basis of spectral data. The H NMR spectra of 9 and 10 showed the olefinic proton (Hi) of 9 at 8 6.03 ppm as a triplet (J = 8.15 Hz.) and of 10 the olefinic proton (H2) at 8 6.14 as a doublet (J = 7.79 Hz). Furthermore, twelve resonances in C NMR spectra for each compound were in a good agreement with the structures of 9 and 10. The other 1,3-dienes, 11 and 12 which contain bromine atom, were isolated in 10% and 8% yield, respectively. We assume that the 11 and 12 were formed by the elimination of HBr from the allylic dibromides 7 and 8, respectively, in the reaction medium or during the chromatography (Scheme 3). Ph Br\ .Br Ph Br /7 Ns Ph -HBr Br Br Ph -HBr Br 11 8 Scheme 3 12 In addition, 11 was also synthesized by the rearrangement of 16 with pyridine and AgC104. It was reported ' that the 2-halo-l,3-dienes were obtained by rearrangement of the dihalocarbene adducts with pyridine. For this reason, in two separate experiments 6 9 4 B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. Acta Chim. Slov. 2003, 50, 419-429. 423 l-phenyl-8,8-dibromobicyclo[5.1.0]octane 16 was reacted with pyridine and AgC104, respectively. In both cases, 11 was isolated as the šole product and not even a trace of 12 was detected in these reactions (Scheme 4). Ph ^Br H v Ph H pyridine(a) P-elimin. Br (^Br a "P Ph AgCI04 --------------------------------3 -AgBr Br Ph ,Br © 11 16 17 11 Scheme 4 The compounds 11 and 12 were easily distinguished from the NMR spectra. The proton NMR spectra of 11 and 12 showed the olefinic protons of 11 at 8 6.48 ppm (J = 8.3 Hz) and at 8 6.20 ppm as a triplet (J = 8.28 Hz), and of the 12 at 8 6.41 as a singlet and at 8 6.03 ppm as a triplet (J = 8.25 Hz). Additionally, the carbon NMR spectra showed twelve signals for each compound. Ali these findings supported the purposed structures of 11 and 12. The formation of products 13 and 14 is surprising. The formation of 13 can reasonably be explained by the intermediacy of the radical 18, which is formed by the abstraction of the etr-hydrogen relative to bromine in 4 with bromine radical. The radical 18 converts into radical 19 with 7T-bond shift. The abstraction of hydrogen of 19 from HBr in the reaction medium leads to the formation of 13 (Scheme 5). Ph ^Br Ph /Br /7 \ Br -HBr Ph ^Br Phv /Br HBr -Br 18 19 13 Scheme 5 Furthermore, benzylic and allylic bromides give the corresponding alcohols by the 10 hydrolysis in the presence of Ag salts. Additionally, it is known that the geminal dibromides can be converted into the corresponding ketones by hydrolysis with Si02 + and/or Ag salt. 4 B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. 424 Acta Chim. Slov. 2003, 50, 419-429. Thus, to further support of the formation of allylic dibromides 4-8, the mixture of compounds obtained from the reaction of 3 with NBS was let to react with AgCIOzi. NMR studies have indicated that the resulting reaction mixture was very complex and consisted of at least seven products. However, C NMR spectrum showed that the two of them were CK,/J-unsaturated ketones 20 and 21 (C = O shifts: 8 200.91, 200.66 ppm and C=C shifts: 8 163.35 and 161.46 ppm, characteristic for et;/J-unsaturated ketones), one of them was alcohol 15 (C-OH shift: 8 70.45 ppm), and the others were 9 and 13. This mixture was submitted to silica gel column chromatography. After repeated column chromatography, we isolated compounds 9, 13, and 15. But we could not separate the CK,/J-unsaturated ketones 20 and 21 as sufficiently pure. Even a trace of the 22 was not detected in this reaction (Scheme 6). Ph NBS AgCI04, Acetone/H20 (9:1) reflux, silica gel Ph ] \ Ph Br Ph OH 9, 21% 13, 12% 15, 18% Ph /P Ph // \ i \ .0 20, 21, 13% Scheme 6 Phv /OH 22 other products 15% The formation of 20 and 21 can be explained by the hydrolysis of 7 and 8 in the presence ot Ag (Scheme 7). Ph Br Br Ag+, H20 --------------------------------3 -AgBr r"\ \^-Br 23 Ph O -HBr 20 Scheme 7 3 B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. Acta Chim. Slov. 2003, 50, 419-429. 425 As the compound 6 contains both benzylic and allylic bromine atom, we estimated that the cation 24 was easily formed by removal of the bromine atom in 6. As the cation 24 is very stable, it can easily be converted to 2-phenyl-l,3-cyclooctadiene (9) by removal of proton (Scheme 8). Pl\ /Br Ph © ph + -H -Br 6 24 9 Scheme 8 Conclusions Five allylic bromides 4-8 were primarily formed in the reaction of 3 with NBS. An attempt to isolate these compounds which are moisture and heat sensitive, led instead to the formation of new compounds 9-12. The formation of these can be explained by the elimination of HBr from the allylic bromides 4-8. Compound 15 was formed by the addition OH to the allylic system 4 whereas compounds 20 and 21 were formed by the c r*+ hydrolysis ot 7 and 8 in the presence ot Ag . In addition, we lsolated the vinyl bromide 13 and saturated dibromide 14. Similar rearrangements have been reported in literature. Experimental Ali solvents were dried and distilled by standard procedures. Compound 18 was synthesized by the literature procedure. Infrared spectra were obtained from films on NaCl plates of solutions (CCU) in 0.1 mm celi on a Jasco FT/IR-430 Spectrometer. H and C NMR spectra were recorded on 200 (50) MHz Varian and 400 (100) MHz Bruker WP-200 Spectrometers, and we reported ? units with TMS as an internal standard. Ali column chromatographies were performed on silica gel (60 mesh, Merck). The elemental analyses were carried out on a CHNS-932 (LEÈO) analyzer. l-Phenylcyclooctene (3). To a stirred Mg (0.95 g, 39.68 mmol) in 25 mL dry tetrahydrofuran (THF) at room temperature bromobenzene 2 mL and a small amount of I2 were added. The mixture was treated to a solution of bromobenzene (6.23 g, 39.68 mmol) in THF (15 mL) over 2 h at 65 °C and stirred for 1 h. then it was cooled to room B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. 426 Acta Chim. Slov. 2003, 50, 419-429. temperature Cyclooctanone 1 (5 g, 39.68 mmol) was added into this mixture and stirred for 3 h. The resulting mixture was extracted with Et20 (3x150 mL). The combined organic extracts were washed with water (300 mL), and dried over MgSC>4. The evaporation of the solvent (30 °C, 20 mmHg) gave alcohol 2 (7.40 g, 90%). To 50 mL of a stirred solution of 2 (7.49 g, 36.27 mmol) in benzene was added 4-toluenesulfonic acid (p-TsOH) (50 mg) and the mixture was refluxed for 3 h. The reaction mixture was washed with water (50 mL) and dried (MgS04). The solvent was removed and the crude product was filtered through a short silica gel column with «-hexane. Evaporation of the solvent gave 3 (4.0 g, 60%) as a colurless liquid. H NMR (400 MHz, CDCI3) 8 7.32 (m, 2H), 7.24 (m, 3H), 5.96 (t, 1H, ./8.28 Hz), 2.57 (m, 2H), 2.23 (m, 2H), 1.58 (m, 2H), 1.47 (m, 6H). C NMR, (100 MHz, CDCI3) 8 143.66, 140.73, 128.68 (2C), 128.41, 126.91, 126.25 (2C), 30.50, 29.97, 28.97, 27.93, 27.43, 26.67. IR (CCI4) v 3072, 3055, 3024, 2925, 2850, 1597, 1493, 1473, 1448, 1355, 1282, 1072, 1022, 937, 898, 843, 764, 696 cm" . Anal. Calcd for C14H18: C 90.26, H 9.74. Found: C 90.30, H 9.76. Reaction of l-phenylcyclooctene (3) with NBS. A mixture of 3 (1 g, 5.4 mmol), iV-bromosuccinimide (0.95 g, 5.40 mmol), AIBN (20 mg), and CCI4 (20 mL) was heated at reflux for 5 h, cooled, and filtered to remove succinimide. The filtrate was washed with water (20 mL) and dried over CaC^. The solvent was removed under reduced pressure. The residue (1.46 g) was chromatographed on silica gel (60 g) eluted with «-hexane. The first fraction: 2-phenyl-l,3-cyclooctadiene (9), (180 mg, 18%), colorless liquid. H NMR (400 MHz, CDCI3) 8 7.33 (m, 2H), 7.22 (m, 2H), 7.14 (m, 1H), 6.03 (t, 1H, J 8.15 Hz), 5.94 (d, 1H, J 11.3 Hz), 5.88 (dt, 1H, J 7.04 and 11.30 Hz), 2.22 (m, 2H), 2.14 (m, 2H), 1.45 (m, 4H). C NMR (100 MHz, CDCI3) 8 141.51, 137.07, 133.98, 129.07, 128.65 (2C), 127.32, 126.99, 126.88 (2C), 28.96, 28.85, 24.63, 22.88. IR (CCI4) v 3078, 3055, 3005, 2952, 2850, 1497, 1492, 1442, 1077, 1022, 918, 862, 781, 696, 523 cm" Anal. Calcd for C14H16: C 91.25, H 8.75. Found: C 91.22, H 8.77. The second and third fraction consisted of a mixture of 10, 11 and 12. This mixture was chromatographed on silica gel, eluted with hexane. The first: 1-Phenyl-1,3-cyclooctadiene (10), (100 mg, 10%). H NMR (400 MHz, CDCI3) 8 7.28 (m, 5H), 6.14 (d, 1H, J1.19 Hz), 5.87 (dd, 1H, J1.52 and 10.88 Hz), 5.66 (dt, 1H, J 6.11 and 11.95 Hz), 2.18 (m, 4H), 1.43 (m, 4H). C NMR (100 MHz, CDCI3) 8 140.71, 139.97, B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. Acta Chim. Slov. 2003, 50, 419-429. 427 138.11, 138.01, 129.07 (2C), 128.09, 127.68 (2C), 126.37, 30.37, 30.10, 26.33, 24.90. IR (CCU) v 3080, 3058, 3015, 2958, 2855, 1499, 1494, 1443, 1079, 1021, 916, 864, 783, 697, 525 cm" . Anal. Calcd for C14H16: C, 91.25; H, 8.75. Found: C, 91.23; H, 8.78. The second: 2-Bromo-3-phenyl-l,3-cyclooctadiene (11), (140 mg, 10%). H NMR (200 MHz, CDCI3) 8 7.34 (m, 5H), 6.48 (t, 1H, ./8.32 Hz), 6.20 (t, 1H, J 8.28 Hz), 2.41 (m, 4H), 1.79 (m, 4H). C NMR (50 MHz, CDCI3) 8 140.27, 138.27, 134.39, 130.36 (2C), 130.09, 129.58, 129.05 (2C), 121.76, 31.46, 30.41, 25.38, 24.96. IR (CCI4) v 3078, 3058, 3024, 2923, 2854, 1598, 1494, 1460, 1444, 1111, 972, 787, 752, 698, 638, 559, 526 cm" . Anal. Calcd for C^HisBr: C, 63.89; H, 5.74. Found: C, 63.87; H, 5.76. The third: 2-Bromo-4-phenyl-l,3-cyclooctadiene (12), (110 mg, 8%). H NMR (400 MHz, CDCI3) 8 7.22 (m, 5H), 6.41 (s, 1H), 6.01 (t, 1H, J 8.25 Hz), 2.63 (m, 2H), 2.18 (m, 2H), 1.55 (m, 4H): C NMR (100 MHz, CDCI3) 8 142.95, 135.14, 132.59, 127.95 (2C), 127.31 (2C), 126.05, 125.90, 124.91, 28.16, 27.13, 26.99, 25.60. Anal. Calcd for Ci4Hi5Br: C 63.89, H 5.74. Found: C 63.88, H 5.74. The fourth fraction: l-bromo-2-phenylcyclooctene (13), (230 mg, 16%), colorless liquid. H NMR (400 MHz, CDCI3) 8 7.25 (m, 2H), 7.14 (m, 1H), 7.10 (m, 2H), 2.74 (t, 2H, J 5.99 Hz), 2.45 (t, 2H, J 5.67 Hz), 1.67 (m, 2H), 1.54 (m, 6H). C NMR (100 MHz, CDCI3) 8 144.32, 140.34, 128.10 (2C), 128.01 (2C), 126.85, 122.44, 37.85, 34.98, 28.95, 28.49, 26.67, 26.17. IR (CCI4) v 3080, 3055, 3024, 2923, 2856, 1597, 1493, 1462, 1442, 1110, 792, 762, 692, 611, 542 cm" . Anal. Calcd for C^H^Br: C 63.41, H 6.46. Found: C 63.40, H, 6.43. The fifth fraction: 2-Phenylcyclooct-2-ene-l-ol (15), (95 mg, 9%), pale yellow viscous oil. H NMR (400 MHz, CDCI3) 8 7.18 (m, 5H), 5.63 (t, 1H, J 8.51 Hz), 4.85 (dd, 1H, J 4.93 and 11.19 Hz), 2.12 (m, 2H), 1.97 (m, 2H), 1.60 (m, 4H), 1.32 (m, 3H). C NMR (100 MHz, CDCI3) 8 143.52, 140.55, 130.21, 128.65 (2C), 128.49 (2C), 127.33, 70.45, 39.27, 30.52, 27.65, 27.29, 24.75. IR (CCI4) v 3444, 3080, 3049, 3024, 2918, 2856, 1683, 1628, 1597, 1493, 1448, 1352, 1285, 1078, 1071, 758, 657 cm" . Anal. Calcd for C14H18O: C 83.12, H 8.97. Found: C 83.14, H, 8.97. The sixth fraction: Other products, (87 mg, 8%), pale yellow viscous oil. 8,8-Dibromo-l-phenylbicyclo[5.1.0]octane (16). To 75 mL of a stirred solution of l-phenylcycloheptene (4.00 g, 23.25 mmol), and potassium ^-butoxide (6.50 g, 58.00 mmol) in hexane a solution of CHBr3 (14.0 g, 55.0 mmol) in 25 mL hexane at 0 °C for B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. 428 Acta Chim. Slov. 2003, 50, 419-429. 1 h was added. Stirring was continued overnight at room temperature. The reaction mixture was added to 100 mL of water with ice and extracted with hexane (3x75 mL). The combined extracts were washed with water (3x50 mL) and dried CaCb. The solvent was removed under reduced pressure and the residue was crystallized from «-hexane/CH2Cl2 (9:1), and 16 was obtained as a colorless solid (5.60 g, mp 42-45 °C, 67%). H NMR (400 MHz, CDCI3) 8 7.22 (m, 5H), 2.36 (m, 1H), 2.18 (m, 1H), 1.95 (m, 1H), 1.82 (m, 3H), 1.45 (m, 2H), 1.31 (m, 1H), 1.18 (m, 2H). C NMR (100 MHz, CDCI3) 8 145.19, 131.56, 130.10 (2C), 128.97 (2C), 49.65, 44.94, 40.99, 39.52, 33.78, 31.48, 29.96, 27.97. IR (KBr) v 3080, 3055, 3024, 2917, 2886, 1602, 1493, 1454, 1443, 1103, 974, 788, 750, 702, 640, 559, 522 cm" . Anal. Calcd for C^H^B^: C 48.87, H 4.69. Found: C 48.88, H 4.67. Reaction of 16 with pyridine. A mixture of 16 (0.50 g, 1.45 mmol) and pyridine (10 mL) was heated at reflux for lh, cooled and added to 50 mL of water. The mixture was washed with Et20 washed with dilute HC1 (150 mL, 1%) and water (100 mL), and dried over CaCb. The solvent was removed under reduced pressure, and the residue was chromatographed on silica gel, eluted with hexane. Compound 11 was obtained in the yield of 45%. Reaction of 16 with AgC104. To 20 mL of a stirred solution of 16 (0.50 g, 1.45 mmol) in acetone/H20 (9:1) AgC104 (0.30 g, 1.45 mmol) was added. The mixture was refluxed overnight, filtered and dried (MgSO/i). The solvent was removed under reduced pressure and the residue was chromatographed on silica gel, eluted with hexane. 2-Bromo-3-phenyl-l,3-cyclooctadiene (11) was obtained in the yield of 12%. The same reaction was also carried out with dioxane/H20 at reflux temperature and 12 was obtained in the yield of 25%. Reaction of 3 with NBS and AgC104. A mixture of 3 (1 g, 5.4 mmol), iV-bromosuccinimide (0.95 g, 5.4 mmol), AIBN (20 mg), and CCI4 (20 mL) was heated at reflux for 5 h, cooled, and filtered to remove succinimide. The filtrate was washed with water (20 mL) and dried over CaCb. The solvent was removed under reduced pressure. The crude product (1.40 g) was dissolved in acetone/H20 (40 mL, 9:1), and B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of.. Acta Chim. Slov. 2003, 50, 419-429. 429 added AgC104 (1.30 g, 6.28 mmol). The mixture was heated at 30 °C for 2 h. The reaction mixture was filtered and dried over MgSOzj. After removal of the solvent, the crude product was chromatographed on silica gel column eluted with hexane/CHCl3 (9:1). The first fraction: 2-Phenyl-l,3-cyclooctadiene (9), (210 mg, 21%), colorless liquid. The second fraction: l-Bromo-2-phenylcyclooctene (13), (160 mg, 12%), colorless liquid. The third fraction: 2-Phenylcyclooct-2-ene-l-ol (15), (190 mg, 18%), pale yellow viscous oil. The fourth fraction: Other products, (160 mg, 15%), pale yellow viscous oil. Acknowledgements The authors are indebted to the department of chemistry (Gaziosmanpa§a University) for financial support of this work (Grant Nr. 2001/25 University Research Fund). Furthermore, we thank to the department of chemistry (Atatiirk University) for 200 MHz NMR spectra and TUBITAK for 400 MHz NMR Spectrometers and Elemental Analysis. References 1. N. A. Petasis, M. A. Patane, Tetrahedron 1992, 48, 5757-5821. 2. L. A. Paquette, Tetrahedron 1975, 31, 2855-2883. 3. G. I. Fray, R. G. Savton, The Chemistry of Cyclooctatetraene Derivatives; Cambridge University Press; Cambridge, 1978. 4. L. A. Paquette, T. J. Watson, D. Friedrich, J. Org. Chem. 1993, 58, 776-778. 5. (a) M. Ceylan, Y. Budak, J. Chem. Research (M) 2002, 9, 937-946. (b) M. Ceylan, Y. Budak, J. Chem. Research (S) 2002, 9, 416-419. 6. A. Da§tan, M. Balci, T. Hökelek, D. Ülkü, O. Büyiikgüngör, Tetrahedron 1994, 35, 10555-10578. 7. A. Da§tan, Y. Ta§kesenligil, F. Tümer, M. Balci, Tetrahedron 1996, 52, 14005-14020. 8. W. E. Parham, R. W. Soeder, J. R. Throckmorton, K. Kunel, R. M. Dodson, J. Am. Chem. Soc. 1965, 87, 321-323. 9. W. E. Parham, R. J. Sperley, J. Org. Chem., 1967, 32, 926-931. 10. M. Ceylan, Y. Budak, J. Chem. Research (S) 2001, 9, 368-369. 11. J. S. Pizey, Synthetic Reagents; Vol. Z/, Chapter 1, Ellis Honvood: Chichester, 1974. Povzetek Reakcija 1-fenilciklooktena (3) z NBS je dala zmes produktov (4-8). S kolonsko kromatografijo smo izolirali vinil bromid 14 in 1,3-diena 9, 10, bromo-l,3-diena 11, 12 in alilni alkohol 15. Reakcija zmesi 4-8 z AgC104 je dala spojine 9, 14, 15 in ?,/?-nenasièena ketona 21 in 22. B. Büyukkidan, i. G. Budak, M. Ceylan: Reaction of Cycloocten-l-ylbenzene With NBS. Synthesis of..