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Formation and structural features of novel cage compounds with a pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton via photolysis of [33](1,3,5)cyclophane1
Tetrahedron Letters 41 (2000) 6803±6807
Formation and structural features of novel cage compounds with a pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton via photolysis of [33](1,3,5)cyclophane1 Kumi Matohara,a,b Chultack Lim,a Mikio Yasutake,a,b Rika Nogita,a,b Toru Koga,a,b Youichi Sakamotoc and Teruo Shinmyozua,* a
Institute for Fundamental Research of Organic Chemistry (IFOC), Kyushu Univeresity, Hakozaki, Fukuoka 812-8581, Japan b Department of Chemistry, Graduate School of Science, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan c Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan Received 13 December 1999; accepted 7 July 2000
Abstract The photolysis of [33](1,3,5)cyclophane 8 in MeOH:2N HCl (17:1 v/v) aorded new polycyclic caged dimethoxy and methoxy±hydroxy compounds 12 and 13 with a novel pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton 7, in addition to methyl ether 9c with the previously reported skeleton 6. The unique structural features of 12 and 13 were elucidated by X-ray structural analysis. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: hexaprismane; photolysis; cyclophanes; polycyclic cage compounds.
The prismanes constitute a fascinating family of (CH)n polyhedra,2 among which cubane 13 has been most intensively studied by Eaton et al.4 It is stable in spite of its highly strained structure. Pentaprismane is also known,5 but the next higher prismane, hexaprismane 3, and its derivatives are still unknown. Despite much eort, they have so far eluded synthesis, mainly due to the lack of proper synthetic routes and expected higher strain energies than those of the lower prismanes.6,7 Gleiter et al. devised a clue to the successful synthesis of the prismane derivatives * Corresponding author. Fax: +81-92-642-2735; e-mail: [email protected] 0040-4039/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S0040-4039(00)01152-7
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via a photochemical [2+2] reaction by attaching trimethylene bridges to the basic skeleton and they demonstrated the synthesis of propella[34]prismane 2 from the corresponding diene.8 In our photochemical approach to the construction of hexaprismane derivatives such as 4, multibridged [3n]cyclophanes (n=3±6),9 in which two benzene rings are completely stacked with interplanar distance of ca. 3.0±3.1 AÊ,10 are used as the precursors. According to this approach, we reported that the photolysis of [33](1,3,5)cyclophane 8 in dry CH2Cl2 aorded a novel polycyclic caged chloride 9a with a bishomopentaprismane skeleton 6, whereas a similar reaction in H2O-saturated CH2Cl2 aorded the alcohol 9b along with the caged ole®n alcohol 10.11a We elucidated their structures based on the 1H and 13C NMR spectra. However, our recent X-ray analyses showed that the structure of 10 is the same as expected, whereas our presumed structure for the alcohol 11b is dierent from the actual one 9b. We would like to correct the structure to 9b, and the detailed structural properties of 9b and 10 will be reported in the near future as a full paper. The photolyses of [34](1,2,4,5)-11b and [34](1,2,3,5)cyclophanes11c also provided polycyclic cages with the same skeleton 5 (Scheme 1).
Scheme 1. Photochemical reactions of 8 in dry CH2Cl2 or CH2Cl2 containing H2O (upper) and in MeOH in the presence of 2N HCl (lower) under low-pressure Hg lamp irradiation
Since our previous experimental results suggest a protonation mechanism,11aÿc we studied the photolysis in acidic conditions. An MeOH:2N HCl solution (17:1 v/v) (1.0210^2 mol L^1) of 8 was irradiated with a low-pressure Hg lamp for 80 min at room temperature under Ar with monitoring of the reaction using the 1H NMR spectra every 20 min. Separation of the reaction mixture by recycled HPLC of GPC type with CHCl3 aorded the recovered 8 (11%), the methoxy compound 9c (2.7%), as well as the dimethoxy and methoxy±hydroxy compounds 12 (11%) and 13 (5.9%) with a new caged structure. Prolonged irradiation gave 12 as a major product (57%). The compound 9c has the same skeleton 6 that we reported previously.11a The structure of the cage was identi®ed to be 1212 and 1313 on the basis of their molecular formula, NMR spectra, and ®nally the X-ray structural analyses.14 Both compounds are composed of a cyclobutane, four cyclopentanes, and four cyclohexanes, and have the pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton 7. The proton-decoupled 13C NMR spectrum of 12 shows 11 signals for the secondary carbons, four for the tertiary carbons, and six for the quaternary carbon atoms, suggesting an
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unsymmetrical structure.12 Compound 13 shows a very similar 13C NMR spectrum. Highly deshielded carbon signals at 86.2 (quat.) and 89.6 (tert.) for 12 as well as 86.2 (quat.) and 79.3 (tert.) for 13 indicate the presence of carbons attached to an oxygen functionality. To our knowledge, the skeleton 7 is a new family of C12H16 and its synthesis has not yet been described in the literature. ORTEP drawings of 12 and the skeleton of 13 are shown in Figs. 1 and 2. One of the C±C bond lengths connected to the upper and lower cyclohexanes, C5±C11 [1.626(7) AÊ] in 12, and C5±C11
Figure 1. ORTEP drawings of 12 (50% probability ellipsoids, hydrogen atoms are omitted for clarity). Selected bond lengths (AÊ): C(1)±C(2) 1.562(7), C(2)±C(3) 1.551(7), C(3)±C(4) 1.519(7), C(4)±C(5) 1.545(7), C(5)±C(6) 1.572(7), C(6)± C(7) 1.543(7), C(7)±C(8) 1.582(7), C(8)±C(9) 1.573(7), C(9)±C(10) 1.522(7), C(10)±C(11) 1.547(7), C(11)± C(12) 1.526(8), C(2)±C(8) 1.572(7), C(3)±C(9) 1.566(7), C(5)±C(11) 1.626(7), C(7)±C(12) 1.520(7)
Figure 2. Crystal structure of the skeleton of 13 (hydrogen atoms are omitted for clarity). Selected bond lengths (AÊ): C(1)±C(2) 1.529(3), C(2)±C(3) 1.563(3), C(3)±C(4) 1.522(3), C(4)±C(5) 1.540(3), C(5)±C(6) 1.561(3), C(6)±C(7) 1.552(3), C(7)±C(8) 1.560(3), C(8)±C(9) 1.566(3), C(9)±C(10) 1.523(3), C(10)±C(11) 1.529(3), C(11)±C(12) 1.538(3), C(2)±C(8) 1.565(3), C(3)±C(9) 1.569(3), C(5)±C(11) 1.593(3), C(7)±C(12) 1.513(3)
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[1.593(3) AÊ] in 13, is abnormally long as compared with the RHF/6-31G* optimized C±C bond length (1.552 AÊ) of a cyclopentane.11b The upper six-membered ring has the distorted boat form of a cyclohexane (Fig. 3); the dihedral angles of the C2±C3±C5±C6 and C2±C1±C6 planes as well as the C2±C3±C5±C6 and C3±C4±C5 planes are, respectively, 51.8 and 44.7 for 12, and 51.2 and 46.6 for 13. The lower six-membered ring has the distorted twist-chair form of a cyclohexane in both cases.
Figure 3. The structures of the upper and lower six-membered rings of 12
Thus, the photochemical reaction of 8 did proceed in MeOH in the presence of a proton source to give 9c as was the case in H2O-saturated CH2Cl2.11a Subsequent protonation to the unbridged carbon atom of the central bicyclo[2.2.0]hexane skeleton of 9c from the upper side may give the secondary carbocation, which is intercepted by MeOH or H2O to give the new products 12 and 13 (Scheme 2).11 Further elaboration of the reaction conditions and our eort towards the isolation of the hexaprimane derivatives are now under intense investigation.
Scheme 2. Plausible reaction mechanism
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Acknowledgements We gratefully acknowledge ®nancial support by a Grant-in-Aid for the Priority Area (A) of Creation of Delocalized Electronic Systems (no. 12020241) from the Ministry of Education, Science, Sports and Culture, Japan. References 1. Multibridged [3n]Cyclophanes, Part 10. 2. For recent reviews, see: (a) Dodziuk, H. In Topics in Stereochemistry, Vol. 21; Eliel, E. L.; Wilen, S. H., Eds.; John Wiley & Sons, 1994. (b) Dodziuk, H. Modern Conformational Analysis; VCH Publishers, 1995. (c) Forman, M. A. Org. Prep. Proced. Int. 1994, 26, 291±320. 3. Eaton, P. E.; Cole, T. W. J. Am. Chem. Soc. 1964, 86, 3157±3158. 4. For reviews, see: (a) Eaton, P. E. Acc. Chem. Res. 1968, 1, 50±57. (b) Eaton, P. E. Tetrahedron 1979, 35, 2189± 2223. (c) Eaton, P. E. Angew. Chem., Int. Ed. Engl. 1992, 31, 1421±1436. 5. Eaton, P. E.; Or, Y. S.; Branca, S. J. J. Am. Chem. Soc. 1981, 103, 2134±2136. 6. (a) Mehta, G.; Padma, S. Tetrahedron Lett. 1987, 28, 1295±1298. (b) Mehta, G.; Padma, S. J. Am. Chem. Soc. 1987, 109, 2212±2213. 7. (a) Higuchi, H.; Takatsu, K.; Otsubo, T.; Sakata, Y.; Misumi, S. Tetrahedron Lett. 1982, 23, 671±672. (b) Higuchi, H.; Kobayashi, E.; Sakata, Y.; Misumi, S. Tetrahedron 1986, 42, 1731±1739. 8. (a) Gleiter, R.; Karcher, M. Angew. Chem., Int. Ed. Engl. 1988, 27, 840±841. (b) Brand, S.; Gleiter, R. Tetrahedron Lett. 1997, 38, 2939±2942. (c) Gleiter, R.; Brand, S. Chem. Eur. J. 1998, 4, 2532±2538. 9. (a) Sakamoto, Y.; Miyoshi, N.; Hirakida, M.; Kusumoto, S.; Kawase, H.; Rudzinski, J. M.; Shinmyozu, T. J. Am. Chem. Soc. 1996, 118, 12267±12275. (b) Sakamoto, Y.; Shinmyozu, T. Recent Res. Devel. in Pure & Applied Chem. 1998, 2, 371±399. (c) Sentou, W.; Satou, T.; Yasutake, M.; Lim, C.; Shinmyozu, T. Eur. J. Org. Chem. 1999, 1223± 1231. 10. Yasutake, M.; Sakamoto, Y.; Onaka, S.; Sako, K.; Tatemitsu, H.; Shinmyozu, T. submitted. 11. (a) Sakamoto, Y.; Kumagai, T.; Matohara, K.; Lim, C.; Shinmyozu, T. Tetrahedron Lett. 1999, 40, 919±922 (Multibridged [3n]Cyclophanes, Part 6). (b) Lim, C.; Yasutake, M.; Shinmyozu, T. Angew. Chem., Int. Ed. Engl. 2000, 39, 578±580 (Multibridged [3n]Cyclophanes, Part 8). (c) Lim, C.; Yasutake, M.; Shinmyozu, T. Tetrahedron Lett. 1999, 40, 6781±6784 (Multibridged [3n]Cyclophanes, Part 9). 12. Selected spectroscopic data and elemental analysis for 12: mp 56±57 C; 13C NMR (CDCl3, DEPT) 19.9 (sec.), 25.0 (sec.), 26.1 (sec.), 32.1 (sec.), 34.0 (sec.), 35.4 (sec.), 36.5 (sec.), 36.6 (sec), 37.4 (sec.), 37.9 (sec.), 40.9 (sec.), 45.1 (tert.), 45.3 (tert.), 48.2 (quat.), 49.2 (quat.), 51.0 (tert.), 51.9 (quat.), 56.4 (quat.), 57.3 (quat.), 59.4 (prim.), 65.0 (prim.), 86.2 (quat.), 89.6 ppm (tert.). EIMS: m/z 340 [M+]. Anal. calcd for C32H2O2.1/8H2O: C, 80.63; H, 9.39%. Found: C, 80.65; H, 9.33%. 13. Selected spectroscopic data and elemental analysis for 13: mp 138±139 C; 13C NMR (CDCl3, DEPT) 19.9 (sec.), 25.4 (sec.), 26.1 (sec.), 31.4 (sec.), 34.0 (sec.), 35.0 (sec.), 35.4 (sec.), 36.1 (sec.), 37.4 (two, sec.), 41.5 (sec.), 45.1 (tert.), 45.3 (tert.), 47.7 (quat.), 49.5 (quat.), 51.0 (tert.), 52.2 (quat.), 56.0 (quat.), 57.6 (quat.), 64.5 (prim.), 79.3 (tert.), 86.2 ppm (quat.). EIMS: m/z 326 [M+]. Anal. calcd for C22H30O2.1/2H2O: C, 79.83; H, 9.28%. Found: C, 79.78; H, 9.13%. 14. Crystal Data for 12: C23H32O2, Mr=340.50, monoclinic space group P21/c (#14), a=9.6909(2), b=24.4120(8), c=8.4755(3) AÊ, =115.234(1) , Z=4, V=1813.748 AÊ3, Mo=0.77 cm^1 (Rigaku RAPID imaging plate), 1742 re¯ections with I>3.00(I), R(Rw)=0.060 (0.079), GOF=1.17. Crystal Data for 13: C22H30O2, Mr=326.47, orthorhombic space group Pbca (#61), a=18.074(4), b=14.006 (3), c=13.445(3) AÊ, Z=8, V=3403.5(2) AÊ3, Mo=0.77 cm^1 (Rigaku RAPID imaging plate), 2182 re¯ections with I>3.00(I), R (Rw)=0.039 (0.048); GOF=0.77. Crystallographic data (excluding structure factor) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-137670 (12) and 137671 (13). Copies of the data can be obtained free of charge upon application to: CCDC, 12 Union Road, Cambridge CB21EZ, UK (fax: (+44)-1223-33603; e-mail: [email protected]).
Formation and structural features of novel cage compounds with a pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton via photolysis of [33](1,3,5)cyclophane1 Kumi Matohara,a,b Chultack Lim,a Mikio Yasutake,a,b Rika Nogita,a,b Toru Koga,a,b Youichi Sakamotoc and Teruo Shinmyozua,* a
Institute for Fundamental Research of Organic Chemistry (IFOC), Kyushu Univeresity, Hakozaki, Fukuoka 812-8581, Japan b Department of Chemistry, Graduate School of Science, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan c Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan Received 13 December 1999; accepted 7 July 2000
Abstract The photolysis of [33](1,3,5)cyclophane 8 in MeOH:2N HCl (17:1 v/v) aorded new polycyclic caged dimethoxy and methoxy±hydroxy compounds 12 and 13 with a novel pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton 7, in addition to methyl ether 9c with the previously reported skeleton 6. The unique structural features of 12 and 13 were elucidated by X-ray structural analysis. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: hexaprismane; photolysis; cyclophanes; polycyclic cage compounds.
The prismanes constitute a fascinating family of (CH)n polyhedra,2 among which cubane 13 has been most intensively studied by Eaton et al.4 It is stable in spite of its highly strained structure. Pentaprismane is also known,5 but the next higher prismane, hexaprismane 3, and its derivatives are still unknown. Despite much eort, they have so far eluded synthesis, mainly due to the lack of proper synthetic routes and expected higher strain energies than those of the lower prismanes.6,7 Gleiter et al. devised a clue to the successful synthesis of the prismane derivatives * Corresponding author. Fax: +81-92-642-2735; e-mail: [email protected] 0040-4039/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S0040-4039(00)01152-7
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via a photochemical [2+2] reaction by attaching trimethylene bridges to the basic skeleton and they demonstrated the synthesis of propella[34]prismane 2 from the corresponding diene.8 In our photochemical approach to the construction of hexaprismane derivatives such as 4, multibridged [3n]cyclophanes (n=3±6),9 in which two benzene rings are completely stacked with interplanar distance of ca. 3.0±3.1 AÊ,10 are used as the precursors. According to this approach, we reported that the photolysis of [33](1,3,5)cyclophane 8 in dry CH2Cl2 aorded a novel polycyclic caged chloride 9a with a bishomopentaprismane skeleton 6, whereas a similar reaction in H2O-saturated CH2Cl2 aorded the alcohol 9b along with the caged ole®n alcohol 10.11a We elucidated their structures based on the 1H and 13C NMR spectra. However, our recent X-ray analyses showed that the structure of 10 is the same as expected, whereas our presumed structure for the alcohol 11b is dierent from the actual one 9b. We would like to correct the structure to 9b, and the detailed structural properties of 9b and 10 will be reported in the near future as a full paper. The photolyses of [34](1,2,4,5)-11b and [34](1,2,3,5)cyclophanes11c also provided polycyclic cages with the same skeleton 5 (Scheme 1).
Scheme 1. Photochemical reactions of 8 in dry CH2Cl2 or CH2Cl2 containing H2O (upper) and in MeOH in the presence of 2N HCl (lower) under low-pressure Hg lamp irradiation
Since our previous experimental results suggest a protonation mechanism,11aÿc we studied the photolysis in acidic conditions. An MeOH:2N HCl solution (17:1 v/v) (1.0210^2 mol L^1) of 8 was irradiated with a low-pressure Hg lamp for 80 min at room temperature under Ar with monitoring of the reaction using the 1H NMR spectra every 20 min. Separation of the reaction mixture by recycled HPLC of GPC type with CHCl3 aorded the recovered 8 (11%), the methoxy compound 9c (2.7%), as well as the dimethoxy and methoxy±hydroxy compounds 12 (11%) and 13 (5.9%) with a new caged structure. Prolonged irradiation gave 12 as a major product (57%). The compound 9c has the same skeleton 6 that we reported previously.11a The structure of the cage was identi®ed to be 1212 and 1313 on the basis of their molecular formula, NMR spectra, and ®nally the X-ray structural analyses.14 Both compounds are composed of a cyclobutane, four cyclopentanes, and four cyclohexanes, and have the pentacyclo[6.4.0.03,7.04,11.05,10]dodecane skeleton 7. The proton-decoupled 13C NMR spectrum of 12 shows 11 signals for the secondary carbons, four for the tertiary carbons, and six for the quaternary carbon atoms, suggesting an
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unsymmetrical structure.12 Compound 13 shows a very similar 13C NMR spectrum. Highly deshielded carbon signals at 86.2 (quat.) and 89.6 (tert.) for 12 as well as 86.2 (quat.) and 79.3 (tert.) for 13 indicate the presence of carbons attached to an oxygen functionality. To our knowledge, the skeleton 7 is a new family of C12H16 and its synthesis has not yet been described in the literature. ORTEP drawings of 12 and the skeleton of 13 are shown in Figs. 1 and 2. One of the C±C bond lengths connected to the upper and lower cyclohexanes, C5±C11 [1.626(7) AÊ] in 12, and C5±C11
Figure 1. ORTEP drawings of 12 (50% probability ellipsoids, hydrogen atoms are omitted for clarity). Selected bond lengths (AÊ): C(1)±C(2) 1.562(7), C(2)±C(3) 1.551(7), C(3)±C(4) 1.519(7), C(4)±C(5) 1.545(7), C(5)±C(6) 1.572(7), C(6)± C(7) 1.543(7), C(7)±C(8) 1.582(7), C(8)±C(9) 1.573(7), C(9)±C(10) 1.522(7), C(10)±C(11) 1.547(7), C(11)± C(12) 1.526(8), C(2)±C(8) 1.572(7), C(3)±C(9) 1.566(7), C(5)±C(11) 1.626(7), C(7)±C(12) 1.520(7)
Figure 2. Crystal structure of the skeleton of 13 (hydrogen atoms are omitted for clarity). Selected bond lengths (AÊ): C(1)±C(2) 1.529(3), C(2)±C(3) 1.563(3), C(3)±C(4) 1.522(3), C(4)±C(5) 1.540(3), C(5)±C(6) 1.561(3), C(6)±C(7) 1.552(3), C(7)±C(8) 1.560(3), C(8)±C(9) 1.566(3), C(9)±C(10) 1.523(3), C(10)±C(11) 1.529(3), C(11)±C(12) 1.538(3), C(2)±C(8) 1.565(3), C(3)±C(9) 1.569(3), C(5)±C(11) 1.593(3), C(7)±C(12) 1.513(3)
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[1.593(3) AÊ] in 13, is abnormally long as compared with the RHF/6-31G* optimized C±C bond length (1.552 AÊ) of a cyclopentane.11b The upper six-membered ring has the distorted boat form of a cyclohexane (Fig. 3); the dihedral angles of the C2±C3±C5±C6 and C2±C1±C6 planes as well as the C2±C3±C5±C6 and C3±C4±C5 planes are, respectively, 51.8 and 44.7 for 12, and 51.2 and 46.6 for 13. The lower six-membered ring has the distorted twist-chair form of a cyclohexane in both cases.
Figure 3. The structures of the upper and lower six-membered rings of 12
Thus, the photochemical reaction of 8 did proceed in MeOH in the presence of a proton source to give 9c as was the case in H2O-saturated CH2Cl2.11a Subsequent protonation to the unbridged carbon atom of the central bicyclo[2.2.0]hexane skeleton of 9c from the upper side may give the secondary carbocation, which is intercepted by MeOH or H2O to give the new products 12 and 13 (Scheme 2).11 Further elaboration of the reaction conditions and our eort towards the isolation of the hexaprimane derivatives are now under intense investigation.
Scheme 2. Plausible reaction mechanism
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Acknowledgements We gratefully acknowledge ®nancial support by a Grant-in-Aid for the Priority Area (A) of Creation of Delocalized Electronic Systems (no. 12020241) from the Ministry of Education, Science, Sports and Culture, Japan. References 1. Multibridged [3n]Cyclophanes, Part 10. 2. For recent reviews, see: (a) Dodziuk, H. In Topics in Stereochemistry, Vol. 21; Eliel, E. L.; Wilen, S. H., Eds.; John Wiley & Sons, 1994. (b) Dodziuk, H. Modern Conformational Analysis; VCH Publishers, 1995. (c) Forman, M. A. Org. Prep. Proced. Int. 1994, 26, 291±320. 3. Eaton, P. E.; Cole, T. W. J. Am. Chem. Soc. 1964, 86, 3157±3158. 4. For reviews, see: (a) Eaton, P. E. Acc. Chem. Res. 1968, 1, 50±57. (b) Eaton, P. E. Tetrahedron 1979, 35, 2189± 2223. (c) Eaton, P. E. Angew. Chem., Int. Ed. Engl. 1992, 31, 1421±1436. 5. Eaton, P. E.; Or, Y. S.; Branca, S. J. J. Am. Chem. Soc. 1981, 103, 2134±2136. 6. (a) Mehta, G.; Padma, S. Tetrahedron Lett. 1987, 28, 1295±1298. (b) Mehta, G.; Padma, S. J. Am. Chem. Soc. 1987, 109, 2212±2213. 7. (a) Higuchi, H.; Takatsu, K.; Otsubo, T.; Sakata, Y.; Misumi, S. Tetrahedron Lett. 1982, 23, 671±672. (b) Higuchi, H.; Kobayashi, E.; Sakata, Y.; Misumi, S. Tetrahedron 1986, 42, 1731±1739. 8. (a) Gleiter, R.; Karcher, M. Angew. Chem., Int. Ed. Engl. 1988, 27, 840±841. (b) Brand, S.; Gleiter, R. Tetrahedron Lett. 1997, 38, 2939±2942. (c) Gleiter, R.; Brand, S. Chem. Eur. J. 1998, 4, 2532±2538. 9. (a) Sakamoto, Y.; Miyoshi, N.; Hirakida, M.; Kusumoto, S.; Kawase, H.; Rudzinski, J. M.; Shinmyozu, T. J. Am. Chem. Soc. 1996, 118, 12267±12275. (b) Sakamoto, Y.; Shinmyozu, T. Recent Res. Devel. in Pure & Applied Chem. 1998, 2, 371±399. (c) Sentou, W.; Satou, T.; Yasutake, M.; Lim, C.; Shinmyozu, T. Eur. J. Org. Chem. 1999, 1223± 1231. 10. Yasutake, M.; Sakamoto, Y.; Onaka, S.; Sako, K.; Tatemitsu, H.; Shinmyozu, T. submitted. 11. (a) Sakamoto, Y.; Kumagai, T.; Matohara, K.; Lim, C.; Shinmyozu, T. Tetrahedron Lett. 1999, 40, 919±922 (Multibridged [3n]Cyclophanes, Part 6). (b) Lim, C.; Yasutake, M.; Shinmyozu, T. Angew. Chem., Int. Ed. Engl. 2000, 39, 578±580 (Multibridged [3n]Cyclophanes, Part 8). (c) Lim, C.; Yasutake, M.; Shinmyozu, T. Tetrahedron Lett. 1999, 40, 6781±6784 (Multibridged [3n]Cyclophanes, Part 9). 12. Selected spectroscopic data and elemental analysis for 12: mp 56±57 C; 13C NMR (CDCl3, DEPT) 19.9 (sec.), 25.0 (sec.), 26.1 (sec.), 32.1 (sec.), 34.0 (sec.), 35.4 (sec.), 36.5 (sec.), 36.6 (sec), 37.4 (sec.), 37.9 (sec.), 40.9 (sec.), 45.1 (tert.), 45.3 (tert.), 48.2 (quat.), 49.2 (quat.), 51.0 (tert.), 51.9 (quat.), 56.4 (quat.), 57.3 (quat.), 59.4 (prim.), 65.0 (prim.), 86.2 (quat.), 89.6 ppm (tert.). EIMS: m/z 340 [M+]. Anal. calcd for C32H2O2.1/8H2O: C, 80.63; H, 9.39%. Found: C, 80.65; H, 9.33%. 13. Selected spectroscopic data and elemental analysis for 13: mp 138±139 C; 13C NMR (CDCl3, DEPT) 19.9 (sec.), 25.4 (sec.), 26.1 (sec.), 31.4 (sec.), 34.0 (sec.), 35.0 (sec.), 35.4 (sec.), 36.1 (sec.), 37.4 (two, sec.), 41.5 (sec.), 45.1 (tert.), 45.3 (tert.), 47.7 (quat.), 49.5 (quat.), 51.0 (tert.), 52.2 (quat.), 56.0 (quat.), 57.6 (quat.), 64.5 (prim.), 79.3 (tert.), 86.2 ppm (quat.). EIMS: m/z 326 [M+]. Anal. calcd for C22H30O2.1/2H2O: C, 79.83; H, 9.28%. Found: C, 79.78; H, 9.13%. 14. Crystal Data for 12: C23H32O2, Mr=340.50, monoclinic space group P21/c (#14), a=9.6909(2), b=24.4120(8), c=8.4755(3) AÊ, =115.234(1) , Z=4, V=1813.748 AÊ3, Mo=0.77 cm^1 (Rigaku RAPID imaging plate), 1742 re¯ections with I>3.00(I), R(Rw)=0.060 (0.079), GOF=1.17. Crystal Data for 13: C22H30O2, Mr=326.47, orthorhombic space group Pbca (#61), a=18.074(4), b=14.006 (3), c=13.445(3) AÊ, Z=8, V=3403.5(2) AÊ3, Mo=0.77 cm^1 (Rigaku RAPID imaging plate), 2182 re¯ections with I>3.00(I), R (Rw)=0.039 (0.048); GOF=0.77. Crystallographic data (excluding structure factor) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-137670 (12) and 137671 (13). Copies of the data can be obtained free of charge upon application to: CCDC, 12 Union Road, Cambridge CB21EZ, UK (fax: (+44)-1223-33603; e-mail: [email protected]).