手性亚砜不对称合成方法研究及其在药物合成中的应用
摘要
手性催化剂作用下的硫醚类化合物的不对称催化氧化，是合成手性亚砜类化合物的简便、有效的方法。本论文以对甲基苯甲硫醚和对硝基苯甲硫醚为底物，研究并比较了20种手性配体作用下，上述硫醚类化合物不对称催化氧化反应的对映选择性，采用的手性配体有：(2R，3R)-酒石酸甲酯，(2R，3R)-酒石酸乙酯，(2R，3R)-酒石酸异丙酯，(2R，3R)-酒石酸苄酯，(2R，3R)-N，N’-二苯基酒石酰胺，(2R，3R)-N，N’-二苄基酒石酰胺，(2R，3R)-N，N’-二间甲苯基酒石酰胺，(2R，3R)-N，N’-二对甲苯基酒石酰胺，R-(+)-联萘二酚，S-(-)-联萘二酚，R-(-)-6，6′-二溴-1，1′-联荼-2，2′-二酚，S-(+)-6，6′-二溴-1，1′-联萘-2，2′-二酚，R-(+)-联萘二胺，S-(-)-联萘二胺，R-(+)-2，2′-N，N′-二(甲基氨基)-1，1′-联萘，S-(-)-2，2′-N，N′-二(甲基氨基)-1，1′-联萘，R-(+)-2，2′-二(甲磺酰氨基)-1，1′-联荼，S-(-)-2，2′-二(甲磺酰氨基)-1，1′-联萘，R-(-)-2，2′-N，N′-二(邻羟基苯亚甲基氨基)-1，1′-联萘，S-(+)-2，2′-N，N′-二(邻羟基苯亚甲基氨基)-1，1，1′-联萘。
将上述手性配体与不同的有机金属化合物、氧化剂组合成多种不对称氧化体系对硫醚进行氧化，发现Ti(O-iPr)_4-(2R，3R)-酒石酸异丙酯-H_2O-TBHP-分子筛(氧化体系Ⅰ)，Ti(O-iPr)_4-[R-(+)-联萘二酚]-H_2O-TBHP(Ⅱ)，Ti(O-iPr)_4-[S-(-)-联萘二酚]-H_2O-TBHP(Ⅲ)，Ti(O-iPr)_4-[R-(-)-6，6′-二溴-1，1′-联萘-2，2′-二酚]-H_2O-TBHP(Ⅳ)，和Ti(O-iPr)_4-[S-(+)-6，6′-二溴-1，1′-联萘-2，2′-二酚]-H_2O-TBHP(Ⅴ)等体系对于对甲基苯甲硫醚的不对称催化氧化均有较好的对映选择性，在这些氧化体系的作用下，产物对甲基苯甲亚砜的e.e.值最高达到77％。其中Ti(O-iPr)_4-(2R，3R)-酒石酸异丙酯-H_2O-TBHP-分子筛(Ⅰ)体系还可用于对硝基苯甲硫醚的不对称催化氧化，产物对硝基苯甲亚砜的e.e.值可以达到61％。
将上述优选出的催化氧化体系用于手性亚砜类药物莫达非尼和奥美拉唑的不对称催化氧化合成之中，使用Ti(O-iPr)_4-[S-(+)-6，6′-二溴-1，1′-联萘-2，2′-二酚]-H_2O-TBHP(Ⅴ)体系氧化莫达非尼前体硫醚化合物为莫达非尼时的收率和e.e.值分别为80％和46％，但前述几种氧化体系用于奥美拉唑的不对称催化氧化合成时未得到理想的结果，其收率和e.e.值仅为35％和9.2％。
同时，还建立了一种与现有工业生产方法相比较，更为简单、有效的合成消旋奥美拉唑的新的氧化方法，收率稳定在82％-92％之间，有希望应用于奥美拉唑的工业化生产。
通过化学合成和拆分制备了二十种光活手性配体。其中合成消旋联萘二胺的方法是新建立的，与文献方法比较收率提高，操作简便，更适合于大量制备。
Catalytic asymmetric oxidation of thioether was generally a simple and effective method in the synthesis of chiral sulfoxide compounds. The enantioselectivity in the catalytic asymmetric oxidative reaction of methyl p-tolyl sulfide and methyl 4-nitrophenyI sulfide was studied in our research using the following 20 chiral ligands: (2R,3R)-dimethyl tartrate, (2R,3R)-diethyl tartrate, (2R,3R)-diisopropyl tartrate, (2R,3R)-dibenzyl tartrate, (2R,3R)-N,N'-diphenyl tartramide, (2R,3R)-N,N'-dibenzyl tartramide, (2R.3R)-N,N'-di-m-tolyl tartramide, (2R,3R)-N,N'-di-p-tolyl tartramide, R-(+)-2,2'-dihydroxy-1,1'-binaphthyl, S-(-)-2,2'-dihydroxy-1,1 '-binaphthyl, R-(-)-6,6'-dibromo-2,2'-dihydroxy-1,1 '-binaphthyl, S-(+)-6,6'-dibromo-2,2'-dihydroxy-1,1 '-binaphthyl, R-(+)-2,2'-diamino-1,1 '-binaphthyl, S-(-)-2,2'-diamino-1,1 '-binaphthyl, R-(+)-2,2'-bis(methylamino)-1,1'-binaphthyl, S-(-)-2,2'-bis(methylamino)-1,1 '-binaphthyl, R-(+)-2,2'-bis(methanesulfonylamino)-1,1 '-binaphthyl, S-(-)-2,2'-bis(methanesulfonylamino)-1,1'-binaphthyl, R-(-)-2,2'-bis[((2-hydroxyphenyl)methylene)amino]-l,l'-binaphthyl, S-(+)-2,2'-bis[((2-hydroxyphenyl)methylene)amino]-1,1'- binaphthyl.Various asymmetric oxidation system were made up of the above chiral ligands, oxidants and different organic transition metal compounds and studied on the asymmetric oxidation of thioether, it is found that all the following 5 oxidation system showed good enantioselectivity in the catalytic asymmetric oxidation of methyl p-tolyl sulfide: Ti(O-iPr)_4-[(2R,3R)-diisopropyl tartrate]-H_2O-TBHP-4aMS (oxidation system I ), Ti(O-iPr)_4-[R-(+)-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (oxidation system II ), Ti(O-iPr)_4-[S-(-)-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (oxidation system III ), Ti(O-iPr)_4-[R-(-)-6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (system IV ), Ti(O-iPr)_4-[S-(+)-6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (system V ), methyl p-tolyl sulfide can be oxidation to corresponding methyl p-tolyl sulfoxide by these systems with e.e. value up to 77%, meanwhile, Ti(O-iPr)_4-(2R,3R)-diisopropyl tartrate-H_2O-TBHP-4a MS (oxidation system I) can also be used in the catalytic asymmetric oxidation of methyl 4-nitrophenyl sulfide to corresponding methyl 4-nitrophenyl sulfoxide with e.e. value up to 61%.The above asymmetric oxidation systems were applied in the synthesis of 2 chiral sulfoxide drugs, Modafinil and Omeprazole, when Ti(O-iPr)_4-[S-(+)-6,6'-dibromo-2,2' -dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (system V ) was used in the oxidation of pro-thioether of Modafinil, Modafinil was achieved with yield of 80％and e. e. value of 46％, but no satisfactory results achieved in the asymmetric oxidation of pro-thioether of Omeprazole to Omeprazole, the chemical yield and e. e. value were only 35％and 9.2％correspondingly.
Meanwhile, a new oxidation method for the synthesis of racemic Omeprazole was found with steady chemical yield between 82～92％, this method was more simple and effective than the present ways and could be hopefully applied in the industrial preparation of Omeprazole.
20 optically active chiral ligands were prepared through chemical synthesis and resolution, new synthetic way to racemic 2, 2'-diamino-1, 1'-binaphthyl was found, which was more convenient and with higher yield than the present reference methods. This new method fits large-scale preparation of 2, 2'-diamino-1, 1'-binaphthyl.
将上述手性配体与不同的有机金属化合物、氧化剂组合成多种不对称氧化体系对硫醚进行氧化，发现Ti(O-iPr)_4-(2R，3R)-酒石酸异丙酯-H_2O-TBHP-分子筛(氧化体系Ⅰ)，Ti(O-iPr)_4-[R-(+)-联萘二酚]-H_2O-TBHP(Ⅱ)，Ti(O-iPr)_4-[S-(-)-联萘二酚]-H_2O-TBHP(Ⅲ)，Ti(O-iPr)_4-[R-(-)-6，6′-二溴-1，1′-联萘-2，2′-二酚]-H_2O-TBHP(Ⅳ)，和Ti(O-iPr)_4-[S-(+)-6，6′-二溴-1，1′-联萘-2，2′-二酚]-H_2O-TBHP(Ⅴ)等体系对于对甲基苯甲硫醚的不对称催化氧化均有较好的对映选择性，在这些氧化体系的作用下，产物对甲基苯甲亚砜的e.e.值最高达到77％。其中Ti(O-iPr)_4-(2R，3R)-酒石酸异丙酯-H_2O-TBHP-分子筛(Ⅰ)体系还可用于对硝基苯甲硫醚的不对称催化氧化，产物对硝基苯甲亚砜的e.e.值可以达到61％。
将上述优选出的催化氧化体系用于手性亚砜类药物莫达非尼和奥美拉唑的不对称催化氧化合成之中，使用Ti(O-iPr)_4-[S-(+)-6，6′-二溴-1，1′-联萘-2，2′-二酚]-H_2O-TBHP(Ⅴ)体系氧化莫达非尼前体硫醚化合物为莫达非尼时的收率和e.e.值分别为80％和46％，但前述几种氧化体系用于奥美拉唑的不对称催化氧化合成时未得到理想的结果，其收率和e.e.值仅为35％和9.2％。
同时，还建立了一种与现有工业生产方法相比较，更为简单、有效的合成消旋奥美拉唑的新的氧化方法，收率稳定在82％-92％之间，有希望应用于奥美拉唑的工业化生产。
通过化学合成和拆分制备了二十种光活手性配体。其中合成消旋联萘二胺的方法是新建立的，与文献方法比较收率提高，操作简便，更适合于大量制备。
Catalytic asymmetric oxidation of thioether was generally a simple and effective method in the synthesis of chiral sulfoxide compounds. The enantioselectivity in the catalytic asymmetric oxidative reaction of methyl p-tolyl sulfide and methyl 4-nitrophenyI sulfide was studied in our research using the following 20 chiral ligands: (2R,3R)-dimethyl tartrate, (2R,3R)-diethyl tartrate, (2R,3R)-diisopropyl tartrate, (2R,3R)-dibenzyl tartrate, (2R,3R)-N,N'-diphenyl tartramide, (2R,3R)-N,N'-dibenzyl tartramide, (2R.3R)-N,N'-di-m-tolyl tartramide, (2R,3R)-N,N'-di-p-tolyl tartramide, R-(+)-2,2'-dihydroxy-1,1'-binaphthyl, S-(-)-2,2'-dihydroxy-1,1 '-binaphthyl, R-(-)-6,6'-dibromo-2,2'-dihydroxy-1,1 '-binaphthyl, S-(+)-6,6'-dibromo-2,2'-dihydroxy-1,1 '-binaphthyl, R-(+)-2,2'-diamino-1,1 '-binaphthyl, S-(-)-2,2'-diamino-1,1 '-binaphthyl, R-(+)-2,2'-bis(methylamino)-1,1'-binaphthyl, S-(-)-2,2'-bis(methylamino)-1,1 '-binaphthyl, R-(+)-2,2'-bis(methanesulfonylamino)-1,1 '-binaphthyl, S-(-)-2,2'-bis(methanesulfonylamino)-1,1'-binaphthyl, R-(-)-2,2'-bis[((2-hydroxyphenyl)methylene)amino]-l,l'-binaphthyl, S-(+)-2,2'-bis[((2-hydroxyphenyl)methylene)amino]-1,1'- binaphthyl.Various asymmetric oxidation system were made up of the above chiral ligands, oxidants and different organic transition metal compounds and studied on the asymmetric oxidation of thioether, it is found that all the following 5 oxidation system showed good enantioselectivity in the catalytic asymmetric oxidation of methyl p-tolyl sulfide: Ti(O-iPr)_4-[(2R,3R)-diisopropyl tartrate]-H_2O-TBHP-4aMS (oxidation system I ), Ti(O-iPr)_4-[R-(+)-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (oxidation system II ), Ti(O-iPr)_4-[S-(-)-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (oxidation system III ), Ti(O-iPr)_4-[R-(-)-6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (system IV ), Ti(O-iPr)_4-[S-(+)-6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (system V ), methyl p-tolyl sulfide can be oxidation to corresponding methyl p-tolyl sulfoxide by these systems with e.e. value up to 77%, meanwhile, Ti(O-iPr)_4-(2R,3R)-diisopropyl tartrate-H_2O-TBHP-4a MS (oxidation system I) can also be used in the catalytic asymmetric oxidation of methyl 4-nitrophenyl sulfide to corresponding methyl 4-nitrophenyl sulfoxide with e.e. value up to 61%.The above asymmetric oxidation systems were applied in the synthesis of 2 chiral sulfoxide drugs, Modafinil and Omeprazole, when Ti(O-iPr)_4-[S-(+)-6,6'-dibromo-2,2' -dihydroxy-1,1'-binaphthyl]-H_2O-TBHP (system V ) was used in the oxidation of pro-thioether of Modafinil, Modafinil was achieved with yield of 80％and e. e. value of 46％, but no satisfactory results achieved in the asymmetric oxidation of pro-thioether of Omeprazole to Omeprazole, the chemical yield and e. e. value were only 35％and 9.2％correspondingly.
Meanwhile, a new oxidation method for the synthesis of racemic Omeprazole was found with steady chemical yield between 82～92％, this method was more simple and effective than the present ways and could be hopefully applied in the industrial preparation of Omeprazole.
20 optically active chiral ligands were prepared through chemical synthesis and resolution, new synthetic way to racemic 2, 2'-diamino-1, 1'-binaphthyl was found, which was more convenient and with higher yield than the present reference methods. This new method fits large-scale preparation of 2, 2'-diamino-1, 1'-binaphthyl.
引文
[1] WO 9424867 (CA 122:89417z)
[2] WO 9425028 (CA 122:64391y)
[3] A. Graul, R. Castaner, J. Castaner, Drugs Fur., 1999,24(11):1178-83
[4] T. Katsuki, K. B. Sharpless, J. Am. Chem. Soc., 1980,102,5974-6
[5] P. Pitchen, H. B. Kagan, Tetrahedron Lett., 1984,1049
[6] P. Pitchen, M. Deshmukh, E. Dunach, H. B. Kagan, J. Am. Chem. Soc., 1984, 106, 8188-93
[7] S. H. Zhao, O. Samuel, H. B. Kagan, Tetrahedron, 1957,43(21),5135-44
[8] S. Miyano, M. Nava, A. Mori, H. Hashimoto, Bull. Chem. Soc. Jpn., 1984,57,2171-6
[9] E. Gruszecka, J. Labelled Compd. Radiopharm.,1953,20,1257
[10] D. W. Cai, D. L. Hughes, T. R. Verhoeven, P. J. Reider, Tetrahedron Lett.,1995, 36(44): 7991-4
[11] E. G. Mata, Phosphur Sulfur Silicon Relat. Elem., 1996, 117, 231-86
[12] C. P. Baird, C. M. Rayner, J. Chem. Soc., Perkin Trans. 1, 1998, 12,1973-2003
[13] M. H. Ali, D. R. Leach, C. E. Schmitz, Synth. Comm., 1998, 28(16): 2969-81
[14] M. Hirano, S. Yakabe, S. Itoh, J. H. Clark, T. Morimoto, Synthesis, 1997,1161-4
[15] P. A. Ganeshpure, W. Adam, Synthesis, 1996, 179
[16] V. A. Petrov, G.Resnati, Chem. Rev., 1996, 96, 1809
[17] F. Chen, J. L. Wan, C. S. Guan, J. S. Yang, H. Zhang, Synth. Comm., 1996, 26, 253
[18] F. Bonadies, F. Deangelis, L. Locati, A. Scettri, Tetrahedron Lett., 1996,37,7129
[19] S. Yamazaki, Bull. Chem. Soc. Jpn., 1996, 69, 2955
[20] M. Hirano, S. Yakabe, J. H. Clark, T. Morimoto, J. Chem. Soc., Perkin Trans. 1, 1996, 2693
[21] V. Khanna, G. C. Maikap, J. Iqbal, Tetrahedron Lett., 1996, 37, 3367
[22] V. G. Nenajdenko, P. V. Vertelezkij, A. B. Koldobskij, I. V. Alabugin, E. S. Balenkova, J. Org. Chem., 1997, 62, 2483
[23] L. L. Rephogle, J. R. Maynarol, J. Org. Chem., 1967, 32, 1909
[24] D. A. Evans, G. G. Andrews, C. L. Sims, J. Am. Chem. Soc., 1971, 93, 4956
[25] H. Hepwort, H. W. Chapham, J. Chem. Soc., 1921, 1188
[26] Y. Gaoni, Tetrahedron Lett., 1977, 4521
[27] B. Kohl, E. Sturm, J. S. Bilfinger, W. A. Simon, U. Kruger, H. Schaefer, G. Rainer, V. Figala, K. Klemn, R. J. Ife, C. A. Leach, J. Med. Chem., 1992,35, 1049-57
[28] WO 18895 (CA 116:128926n)
[29] R. Johnson, W. G. Phillips, J. Org. Chem., 1967, 32, 3233
[30] H. D. Durst, J. W. Zubrick, G. R. Kieczykowski, Tetrahedron Lett., 1974, 1777
[31] S. Toyonari, K.Toshio, M. Jinsei, T. Shigeo, O. Masaya, Bioorg. Chem., 1981,10(3): 311-23
[32] S. Colona, N. Gaggero, M. Leone, P. Pasta, Tetrahedron, 1991, 47(39):8385-98
[33] O. Horomichi, M. Shinsuke, S. Takeshi, Chem. Lett., 1984, 2, 205-8
[34] C. Stefano, G. Nicoletta, C. Luigi, C. Giacomo, P. Piero, Tetrahedron: Asymmetry 1992, 3(1): 95-106
[35] S. Colonna, N. Gaggero, A. Manfredi, Biochemistry, 1990, 29(46):10465-8
[36] K. Burgess, I. Henderson, Tetrahedron Lett., 1989, 30(28):3633-6
[37] O. Horomichi, M. Shinsuke, O. Yasushi, S. Takeshi, Chem. Lett., 1989,4,625-8
[38] A. G. Katopodis, H. A. Smith, S. W. Moy, J. Am. Chem. Soc., 1988, 110(3):897-9
[39] P. Pitchen, H. B. Kagan, Tetrahedron Lett., 1984, 1049
[40] P. Pitchen, M. Deshmukn, E. Dunach, H. B. Kagan, J. Am. Chem. Soc., 1984, 106(26), 8188-93
[41] S. H. Zhao, O. Samuel, H. B. Kagan, Tetrahedron, 1987,43(21): 5135-44
[42] J. M. Brunel, H. B. Kagan, Synlett., 1996, 4, 404-6
[43] J. M. Brunel, P. Diter, M. Duetsch, H. B. Kagan, J. Org. Chem., 1995,60(24),8086-8
[44] M. I. Donnoli, S. Superchi, C. Rosini, J. Org. Chem., 1998, 63(25), 9392-5
[45] S. Superchi, M. I. Donnoli, C. Rosini, Tetrahedron Lett., 1998, 39, 8541-4
[46] N. Komatsu, M. Hashizume, T. Sugita, S. Uemura, J. Org. Chem., 1993, 58(26), 7624-6
[47] N. Komatsu, M. Hashizume, T. Sugita, S. Uemura, J. Org. Chem., 1993, 58(17), 4529-33
[48] S. Arriigo, B. Francesco, L. Alessanclva, S. Angela, S. Annunziata, Tetrahedron: Asymmetry 1996, 7(3): 657-8
[49] C. Bolm, F. Bienewald, Angew. Chem. Int. Ed. Engl., 1995, 34(23/24), 2640-2
[50] A. H. Vetter, A. Berkessel, Tetrahedron Lett., 1998, 39, 1741-4
[51] K. Noda, N. Hosoya, R. Irie, Y. Yamashita, T. Katsuki, Tetrahedron, 1994, 50(32), 9609-18
[52] C. Kokubo, T. Katsuki, Tetrahedron, 1996, 52(44), 13895-900
[53] W. Adam, M. N. Korb, K. J. Roschmann, C. R. S. MolIer, J. Org. Chem., 1998, 63(10), 3423-8
[54] I. Tsuneo, K. Hiroyasu, Chem. Lett., 1986, 6, 967-8
[55] F. A. Davis, J. C. Towson, M. C. Weismiiler, S. Lal, P. J. Carroll, J. Am. Chem. Soc., 1988, 110 (25), 8477-82
[56] G. Glahsl, R. Herrmann, J. Chem. Soc., Perkin Trans. 1, 1988, 7, 1753-7
[57] F. A. Davis, R. T. Reddy, W. Han, P. J. Carroll, J. Am. Chem. Soc., 1992, 114 (4), 1428-37
[58] F. A. Davis, J. P. McCauley, S. Chattopadhyay, J. C. Towson, I. Tavanaiepour, J. Am. Chem. Soc., 1987, 109 (11), 3370-7
[59] W. B. Jennings, M. J. Kochanewycz, C. J. Lovely, D. R. Boyd, J. Chem. Soc. Chem. Comm., 1994, 22, 2569-70
[60] H. Sakuraba, K. Natori, Y. Tanaka, J. Org. Chem., 1991, 56(13), 4124-9
[61] K. R. Rao, P. B. Sattur, J. Chem. Soc. Chem. Comm., 1989, 6, 342-3
[62] T. Yoshio, S. Eigo, JP 02231466 (CA 114: P 142870e)
[63] B. Albrecht, F. Matthias, Tetrahedron." Asymmetry 1996, 7(3): 671-2
[64] K. K. Andersen, Tetrahedron Lett., 1962, 93
[65] D, N, Harpp, S. M. Vines, J. P. Montillier, T. H. Chan, J. Org. Chem., 1976, 41, 3987
[66] J. K. Whitesell, M. S. Wang, J. Org. Chem., 1991, 56(14), 4552-4
[67] F. Rebiere, H. B. Kagan, Tetrahedron Lett., 1989, 30(28),3659-62
[68] S. C. Benson, J. K. Snyder, Tetrahedron Lett., 1991, 32(42), 5885-8
[69] W. Oppolzer, O. Froelich, C. W. Zamar, G. Bemardinelli, Tetrahedron Lett., 1997, 38(16), 2825-8
[70] SE 9400509
[71] WO 9427988
[2] WO 9425028 (CA 122:64391y)
[3] A. Graul, R. Castaner, J. Castaner, Drugs Fur., 1999,24(11):1178-83
[4] T. Katsuki, K. B. Sharpless, J. Am. Chem. Soc., 1980,102,5974-6
[5] P. Pitchen, H. B. Kagan, Tetrahedron Lett., 1984,1049
[6] P. Pitchen, M. Deshmukh, E. Dunach, H. B. Kagan, J. Am. Chem. Soc., 1984, 106, 8188-93
[7] S. H. Zhao, O. Samuel, H. B. Kagan, Tetrahedron, 1957,43(21),5135-44
[8] S. Miyano, M. Nava, A. Mori, H. Hashimoto, Bull. Chem. Soc. Jpn., 1984,57,2171-6
[9] E. Gruszecka, J. Labelled Compd. Radiopharm.,1953,20,1257
[10] D. W. Cai, D. L. Hughes, T. R. Verhoeven, P. J. Reider, Tetrahedron Lett.,1995, 36(44): 7991-4
[11] E. G. Mata, Phosphur Sulfur Silicon Relat. Elem., 1996, 117, 231-86
[12] C. P. Baird, C. M. Rayner, J. Chem. Soc., Perkin Trans. 1, 1998, 12,1973-2003
[13] M. H. Ali, D. R. Leach, C. E. Schmitz, Synth. Comm., 1998, 28(16): 2969-81
[14] M. Hirano, S. Yakabe, S. Itoh, J. H. Clark, T. Morimoto, Synthesis, 1997,1161-4
[15] P. A. Ganeshpure, W. Adam, Synthesis, 1996, 179
[16] V. A. Petrov, G.Resnati, Chem. Rev., 1996, 96, 1809
[17] F. Chen, J. L. Wan, C. S. Guan, J. S. Yang, H. Zhang, Synth. Comm., 1996, 26, 253
[18] F. Bonadies, F. Deangelis, L. Locati, A. Scettri, Tetrahedron Lett., 1996,37,7129
[19] S. Yamazaki, Bull. Chem. Soc. Jpn., 1996, 69, 2955
[20] M. Hirano, S. Yakabe, J. H. Clark, T. Morimoto, J. Chem. Soc., Perkin Trans. 1, 1996, 2693
[21] V. Khanna, G. C. Maikap, J. Iqbal, Tetrahedron Lett., 1996, 37, 3367
[22] V. G. Nenajdenko, P. V. Vertelezkij, A. B. Koldobskij, I. V. Alabugin, E. S. Balenkova, J. Org. Chem., 1997, 62, 2483
[23] L. L. Rephogle, J. R. Maynarol, J. Org. Chem., 1967, 32, 1909
[24] D. A. Evans, G. G. Andrews, C. L. Sims, J. Am. Chem. Soc., 1971, 93, 4956
[25] H. Hepwort, H. W. Chapham, J. Chem. Soc., 1921, 1188
[26] Y. Gaoni, Tetrahedron Lett., 1977, 4521
[27] B. Kohl, E. Sturm, J. S. Bilfinger, W. A. Simon, U. Kruger, H. Schaefer, G. Rainer, V. Figala, K. Klemn, R. J. Ife, C. A. Leach, J. Med. Chem., 1992,35, 1049-57
[28] WO 18895 (CA 116:128926n)
[29] R. Johnson, W. G. Phillips, J. Org. Chem., 1967, 32, 3233
[30] H. D. Durst, J. W. Zubrick, G. R. Kieczykowski, Tetrahedron Lett., 1974, 1777
[31] S. Toyonari, K.Toshio, M. Jinsei, T. Shigeo, O. Masaya, Bioorg. Chem., 1981,10(3): 311-23
[32] S. Colona, N. Gaggero, M. Leone, P. Pasta, Tetrahedron, 1991, 47(39):8385-98
[33] O. Horomichi, M. Shinsuke, S. Takeshi, Chem. Lett., 1984, 2, 205-8
[34] C. Stefano, G. Nicoletta, C. Luigi, C. Giacomo, P. Piero, Tetrahedron: Asymmetry 1992, 3(1): 95-106
[35] S. Colonna, N. Gaggero, A. Manfredi, Biochemistry, 1990, 29(46):10465-8
[36] K. Burgess, I. Henderson, Tetrahedron Lett., 1989, 30(28):3633-6
[37] O. Horomichi, M. Shinsuke, O. Yasushi, S. Takeshi, Chem. Lett., 1989,4,625-8
[38] A. G. Katopodis, H. A. Smith, S. W. Moy, J. Am. Chem. Soc., 1988, 110(3):897-9
[39] P. Pitchen, H. B. Kagan, Tetrahedron Lett., 1984, 1049
[40] P. Pitchen, M. Deshmukn, E. Dunach, H. B. Kagan, J. Am. Chem. Soc., 1984, 106(26), 8188-93
[41] S. H. Zhao, O. Samuel, H. B. Kagan, Tetrahedron, 1987,43(21): 5135-44
[42] J. M. Brunel, H. B. Kagan, Synlett., 1996, 4, 404-6
[43] J. M. Brunel, P. Diter, M. Duetsch, H. B. Kagan, J. Org. Chem., 1995,60(24),8086-8
[44] M. I. Donnoli, S. Superchi, C. Rosini, J. Org. Chem., 1998, 63(25), 9392-5
[45] S. Superchi, M. I. Donnoli, C. Rosini, Tetrahedron Lett., 1998, 39, 8541-4
[46] N. Komatsu, M. Hashizume, T. Sugita, S. Uemura, J. Org. Chem., 1993, 58(26), 7624-6
[47] N. Komatsu, M. Hashizume, T. Sugita, S. Uemura, J. Org. Chem., 1993, 58(17), 4529-33
[48] S. Arriigo, B. Francesco, L. Alessanclva, S. Angela, S. Annunziata, Tetrahedron: Asymmetry 1996, 7(3): 657-8
[49] C. Bolm, F. Bienewald, Angew. Chem. Int. Ed. Engl., 1995, 34(23/24), 2640-2
[50] A. H. Vetter, A. Berkessel, Tetrahedron Lett., 1998, 39, 1741-4
[51] K. Noda, N. Hosoya, R. Irie, Y. Yamashita, T. Katsuki, Tetrahedron, 1994, 50(32), 9609-18
[52] C. Kokubo, T. Katsuki, Tetrahedron, 1996, 52(44), 13895-900
[53] W. Adam, M. N. Korb, K. J. Roschmann, C. R. S. MolIer, J. Org. Chem., 1998, 63(10), 3423-8
[54] I. Tsuneo, K. Hiroyasu, Chem. Lett., 1986, 6, 967-8
[55] F. A. Davis, J. C. Towson, M. C. Weismiiler, S. Lal, P. J. Carroll, J. Am. Chem. Soc., 1988, 110 (25), 8477-82
[56] G. Glahsl, R. Herrmann, J. Chem. Soc., Perkin Trans. 1, 1988, 7, 1753-7
[57] F. A. Davis, R. T. Reddy, W. Han, P. J. Carroll, J. Am. Chem. Soc., 1992, 114 (4), 1428-37
[58] F. A. Davis, J. P. McCauley, S. Chattopadhyay, J. C. Towson, I. Tavanaiepour, J. Am. Chem. Soc., 1987, 109 (11), 3370-7
[59] W. B. Jennings, M. J. Kochanewycz, C. J. Lovely, D. R. Boyd, J. Chem. Soc. Chem. Comm., 1994, 22, 2569-70
[60] H. Sakuraba, K. Natori, Y. Tanaka, J. Org. Chem., 1991, 56(13), 4124-9
[61] K. R. Rao, P. B. Sattur, J. Chem. Soc. Chem. Comm., 1989, 6, 342-3
[62] T. Yoshio, S. Eigo, JP 02231466 (CA 114: P 142870e)
[63] B. Albrecht, F. Matthias, Tetrahedron." Asymmetry 1996, 7(3): 671-2
[64] K. K. Andersen, Tetrahedron Lett., 1962, 93
[65] D, N, Harpp, S. M. Vines, J. P. Montillier, T. H. Chan, J. Org. Chem., 1976, 41, 3987
[66] J. K. Whitesell, M. S. Wang, J. Org. Chem., 1991, 56(14), 4552-4
[67] F. Rebiere, H. B. Kagan, Tetrahedron Lett., 1989, 30(28),3659-62
[68] S. C. Benson, J. K. Snyder, Tetrahedron Lett., 1991, 32(42), 5885-8
[69] W. Oppolzer, O. Froelich, C. W. Zamar, G. Bemardinelli, Tetrahedron Lett., 1997, 38(16), 2825-8
[70] SE 9400509
[71] WO 9427988