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Current Organic Chemistry

Editor-in-Chief

ISSN (Print): 1385-2728
ISSN (Online): 1875-5348

Review Article

The Chemical Synthesis of the 1-C-Alkyl Substituted Pyrrolidine and Piperidine Iminosugar Natural Products and their Analogues

Author(s): Brendan J. Byatt and Stephen G. Pyne*

Volume 26, Issue 23, 2022

Published on: 03 February, 2023

Page: [2071 - 2097] Pages: 27

DOI: 10.2174/1385272827666230124150741

Price: $65

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Abstract

A review of the chemical synthesis of the 1-C-alkyl substituted pyrrolidine and piperidine iminosugar natural products and their analogues (where the alkyl chain comprises two or more carbons) is provided. These syntheses can be grouped into nine different synthetic strategies that share a common approach toward installing the alkyl substituent. These include nucleophilic addition to aldimines; Grignard additions to glycosylamines, cyclic imides, and carbohydrates; Weinreb ketone synthesis; nucleophilic addition to cyclic nitrones; the Overmann rearrangement; the allylation of hemiaminals; and the Petasis borono-Mannich reaction. The broussonetine alkaloids have proven popular synthetic targets to develop new synthetic methods and verify these target molecules' structures and stereochemistry.

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[1]
Watson, A.A.; Fleet, G.W.J.; Asano, N.; Molyneux, R.J.; Nash, R.J. Polyhydroxylated alkaloids — natural occurrence and therapeutic applications. Phytochemistry, 2001, 56(3), 265-295.
[http://dx.doi.org/10.1016/S0031-9422(00)00451-9] [PMID: 11243453]
[2]
Nash, R.J.; Kato, A.; Yu, C-Y.; Fleet, G.W.J. Iminosugars as glycosyltransferase inhibitors. Future Med. Chem., 2011, 3, 1513-1521.
[http://dx.doi.org/10.4155/fmc.11.117] [PMID: 21882944]
[3]
Horne, G.; Wilson, F.X.; Tinsley, J.; Williams, D.H.; Storer, R. Iminosugars past, present and future: Medicines for tomorrow. Drug Discov. Today, 2011, 16(3-4), 107-118.
[http://dx.doi.org/10.1016/j.drudis.2010.08.017] [PMID: 20817006]
[4]
Conforti, I.; Marra, A. Iminosugars as therapeutic agents: Recent advances and promising trends. Org. Biomol. Chem., 2021, 19, 5439-5475.
[http://dx.doi.org/10.1039/D1OB00382H] [PMID: 33881114]
[5]
Fleet, G.W.J.; Smith, P.W. Enantiospecific syntheses of deoxymannojirimycin, fagomine and 2r,5r-dihydroxymethyl-3r,4r-dihydroxypyrrolidine from D-glucose. Tetrahedron Lett., 1985, 26(11), 1469-1472.
[http://dx.doi.org/10.1016/S0040-4039(00)99073-7]
[6]
Asano, N.; Oseki, K.; Tomioka, E.; Kizu, H.; Matsui, K. N-containing sugars fromMorus alba and their glycosidase inhibitory activities. Carbohydr. Res., 1994, 259(2), 243-255.
[http://dx.doi.org/10.1016/0008-6215(94)84060-1] [PMID: 8050098]
[7]
Yamatake, Y.; Shibata, M.; Nagai, M. Pharmacological studies on root bark of mulberry tree (Morus alba L.). Jpn. J. Pharmacol., 1976, 26(4), 461-469.
[http://dx.doi.org/10.1254/jjp.26.461] [PMID: 1003702]
[8]
Sekioka, T.; Shibano, M.; Kusano, G. Three trihydroxypiperidines, glycosidase inhibitors, from eupatorium fortunei. Turz. Nat. Med., 1995, 49, 332-335.
[9]
Watson, A.A.; Nash, R.J.; Wormald, M.R.; Harvey, D.J.; Dealler, S.; Lees, E.; Asano, N.; Kizu, H.; Kato, A.; Griffiths, R.C.; Cairns, A.J.; Fleet, G.W.J. Glycosidase-inhibiting pyrrolidine alkaloids from Hyacinthoides non-scripta. Phytochemistry, 1997, 46(2), 255-259.
[http://dx.doi.org/10.1016/S0031-9422(97)00282-3]
[10]
Nash, R.J.; Watson, A.A.; Winters, A.L.; Fleet, G.W.J.; Wormald, M.R.; Dealler, S.; Lees, E.; Asano, N.; Molyneux, R.J. Glycosidase Inhibitors in British Plants as Causes of Livestock Disorders Toxic Plants and Other Natural Toxicants; Garland, T; Barr, A.C., Ed.; CABI: New York, USA, 1998, pp. 280-284.
[11]
Kato, A.; Adachi, I.; Miyauchi, M.; Ikeda, K.; Komae, T.; Kizu, H.; Kameda, Y.; Watson, A.A.; Nash, R.J.; Wormald, M.R.; Fleet, G.W.J.; Asano, N. Polyhydroxylated pyrrolidine and pyrrolizidine alkaloids from Hyacinthoides non-scripta and Scilla campanulata. Carbohydr. Res., 1999, 316(1-4), 95-103.
[http://dx.doi.org/10.1016/S0008-6215(99)00043-9] [PMID: 10515698]
[12]
Yan, R.Y.; Wang, H.Q.; Kang, J.; Chen, R.Y. Pyrrolidine-type iminosugars from leaves of Suregada glomerulata. Carbohydr. Res., 2014, 384, 9-12.
[http://dx.doi.org/10.1016/j.carres.2013.11.004] [PMID: 24334235]
[13]
Byatt, B.J.; Kato, A.; Pyne, S.G. Synthesis and structural revision of glyphaeaside C. Org. Lett., 2021, 23(10), 4029-4033.
[http://dx.doi.org/10.1021/acs.orglett.1c01248] [PMID: 33929196]
[14]
Kato, A.; Hollinshead, J.; Yamashita, Y.; Nakagawa, S.; Koike, Y.; Adachi, I.; Yu, C.Y.; Fleet, G.W.J.; Nash, R.J. An α-glucoside of 1,4-dideoxy-1,4-imino-d-lyxitol with an eleven carbon side chain. Phytochem. Lett., 2010, 3(4), 230-233.
[http://dx.doi.org/10.1016/j.phytol.2010.08.006]
[15]
Shibano, M.; Kitagawa, S.; Nakamura, S.; Akazawa, N.; Kusano, G. Studies on the constituents of Broussonetia species. II. Six new pyrrolidine alkaloids, broussonetine A, B, E, F and broussonetinine A and B, as inhibitors of glycosidases from Broussonetia kazinoki Sieb. Chem. Pharm. Bull., 1997, 45(4), 700-705.
[http://dx.doi.org/10.1248/cpb.45.700] [PMID: 9145506]
[16]
Asano, N.; Ikeda, K.; Kasahara, M.; Arai, Y.; Kizu, H. Glycosidase-inhibiting pyrrolidines and pyrrolizidines with a long side chain in Scilla peruviana. J. Nat. Prod., 2004, 67(5), 846-850.
[http://dx.doi.org/10.1021/np0499721] [PMID: 15165148]
[17]
Kato, A.; Kato, N.; Adachi, I.; Hollinshead, J.; Fleet, G.W.J.; Kuriyama, C.; Ikeda, K.; Asano, N.; Nash, R.J. Isolation of glycosidase-inhibiting hyacinthacines and related alkaloids from Scilla socialis. J. Nat. Prod., 2007, 70(6), 993-997.
[http://dx.doi.org/10.1021/np0700826] [PMID: 17536859]
[18]
Ikeda, K.; Takahashi, M.; Nishida, M.; Miyauchi, M.; Kizu, H.; Kameda, Y.; Arisawa, M.; Watson, A.A.; Nash, R.J.; Fleet, G.W.J.; Asano, N. Homonojirimycin analogues and their glucosides from Lobelia sessilifolia and Adenophora spp. (Campanulaceae). Carbohydr. Res., 1999, 323(1-4), 73-80.
[http://dx.doi.org/10.1016/S0008-6215(99)00246-3] [PMID: 10782288]
[19]
Yan, R.Y. Wang, H.Q.; Liu, C.; Kang, J.; Chen, R.Y. α-Glucosidase-inhibitory iminosugars from the leaves of Suregada glomerulata. Bioorg. Med. Chem., 2013, 21(21), 6796-6803.
[http://dx.doi.org/10.1016/j.bmc.2013.07.048] [PMID: 23993676]
[20]
Segraves, N.L.; Crews, P. A Madagascar Sponge Batzella sp. as a source of alkylated iminosugars. J. Nat. Prod., 2005, 68(1), 118-121.
[http://dx.doi.org/10.1021/np049763g] [PMID: 15679333]
[21]
Godin, G.; Compain, P.; Masson, G.; Martin, O.R. A general strategy for the practical synthesis of nojirimycin C-glycosides and analogues. Extension to the first reported example of an iminosugar 1-phosphonate. J. Org. Chem., 2002, 67(20), 6960-6970.
[http://dx.doi.org/10.1021/jo0203903] [PMID: 12353989]
[22]
Reitz, A.B.; Baxter, E.W. Pyrrolidine and piperidine aminosugars from dicarbonyl sugars in one step. Concise synthesis of 1-deoxynojirimycin. Tetrahedron Lett., 1990, 31(47), 6777-6780.
[http://dx.doi.org/10.1016/S0040-4039(00)97169-7]
[23]
Godin, G.; Compain, P.; Martin, O.R. General access to iminosugar C-glycoside building blocks by means of cross-metathesis: A gateway to glycoconjugate mimetics. Org. Lett., 2003, 5(18), 3269-3272.
[http://dx.doi.org/10.1021/ol035117h] [PMID: 12943404]
[24]
Godin, G. Compain, P.; Martin, O.R.; Ikeda, K.; Yu, L.; Asano, N. α-1-C-Alkyl-1-deoxynojirimycin derivatives as potent and selective inhibitors of intestinal isomaltase: Remarkable effect of the alkyl chain length on glycosidase inhibitory profile. Bioorg. Med. Chem. Lett., 2004, 14(24), 5991-5995.
[http://dx.doi.org/10.1016/j.bmcl.2004.09.086] [PMID: 15546715]
[25]
Lay, L.; Nicotra, F.; Paganini, A.; Pangrazio, C.; Panza, L. A new procedure for the synthesis of azasugars. Tetrahedron Lett., 1993, 34(28), 4555-4558.
[http://dx.doi.org/10.1016/0040-4039(93)88084-V]
[26]
Cipolla, L.; Lay, L.; Nicotra, F.; Pangrazio, C.; Panza, L. Synthesis of azasugars by Grignard reaction on glycosylamines. Tetrahedron, 1995, 51(16), 4679-4690.
[http://dx.doi.org/10.1016/0040-4020(95)00151-W]
[27]
Cipolla, L.; La Ferla, B.; Peri, F.; Nicotra, F. A new procedure for the synthesis of C-glycosides of nojirimycin. Chem. Commun., 2000, (14), 1289-1290.
[http://dx.doi.org/10.1039/b003877f]
[28]
Von der Osten, C.H.; Sinskey, A.J.; Barbas, C.F., III; Pederson, R.L.; Wang, Y.F.; Wong, C.H. Use of a recombinant bacterial fructose-1,6-diphosphate aldolase in aldol reactions: Preparative syntheses of 1-deoxynojirimycin, 1-deoxymannojirimycin, 1,4-dideoxy-1,4-imino-D-arabinitol, and fagomine. J. Am. Chem. Soc., 1989, 111(11), 3924-3927.
[http://dx.doi.org/10.1021/ja00193a025]
[29]
Baxter, E.W.; Reitz, A.B. Expeditious synthesis of aza sugars by the double reductive amination of dicarbonyl sugars. J. Org. Chem., 1994, 59(11), 3175-3185.
[http://dx.doi.org/10.1021/jo00090a040]
[30]
Cipolla, L.; Palma, A.; Ferla, B.L.; Nicotra, F. Synthesis of nojirimycin C-glycosides. J. Chem. Soc., Perkin Trans. 1, 2002, 2(19), 2161-2165.
[http://dx.doi.org/10.1039/b206623h]
[31]
Yan, L.; Kahne, D. p-Methoxybenzyl ethers as acid-labile protecting groups in oligosaccharide synthesis. Synlett, 1995, 1995(SI), 523-524.
[http://dx.doi.org/10.1055/s-1995-5291]
[32]
Forbes, I.T.; Johnson, C.N.; Thompson, M. Syntheses of functionalised pyrido[2,3-b]indoles. J. Chem. Soc., Perkin Trans. 1, 1992, (2), 275-281.
[http://dx.doi.org/10.1039/p19920000275]
[33]
Schönemann, W.; Gallienne, E.; Compain, P.; Ikeda, K.; Asano, N.; Martin, O.R. Synthesis of new β-1-C-alkylated imino-L-iditols: A comparative study of their activity as β-glucocerebrosidase inhibitors. Bioorg. Med. Chem., 2010, 18(7), 2645-2650.
[http://dx.doi.org/10.1016/j.bmc.2010.02.027] [PMID: 20231099]
[34]
Dondoni, A.; Perrone, D. A convenient synthesis of iminosugar-C-glycosides via organometallic addition to N-benzyl-N-glycosylhydroxylamines. Tetrahedron, 2003, 59(24), 4261-4273.
[http://dx.doi.org/10.1016/S0040-4020(03)00631-8]
[35]
Schönemann, W.; Gallienne, E.; Ikeda-Obatake, K.; Asano, N.; Nakagawa, S.; Kato, A.; Adachi, I.; Górecki, M.; Frelek, J.; Martin, O.R. Glucosylceramide mimics: Highly potent GCase inhibitors and selective pharmacological chaperones for mutations associated with types 1 and 2 Gaucher disease. ChemMedChem, 2013, 8(11), 1805-1817.
[http://dx.doi.org/10.1002/cmdc.201300327] [PMID: 24115322]
[36]
Wennekes, T.; van den Berg, R.J.B.H.N.; Boltje, T.J.; Donker-Koopman, W.E.; Kuijper, B.; van der Marel, G.A.; Strijland, A.; Verhagen, C.P.; Aerts, J.M.F.G.; Overkleeft, H.S. Synthesis and evaluation of lipophilic Aza-C-glycosides as inhibitors of glucosylceramide metabolism. Eur. J. Org. Chem., 2010, 2010(7), 1258-1283.
[http://dx.doi.org/10.1002/ejoc.200901208]
[37]
Lahiri, R.; Suman Reddy, Y.; Kulkarni, S.A.; Vankar, Y.D. Synthesis of unnatural indolizidines, pyrrolizidine and C-alkyl iminosugars from sugar derived hemiaminals. RSC Advances, 2013, 3(45), 23242-23254.
[http://dx.doi.org/10.1039/c3ra43510e]
[38]
Yoda, H.; Shimojo, T.; Takabe, K. First total synthesis of a new tetrasubstituted pyrrolidine alkaloid, broussonetine C. Tetrahedron Lett., 1999, 40(7), 1335-1336.
[http://dx.doi.org/10.1016/S0040-4039(98)02605-7]
[39]
Perlmutter, P.; Vounatsos, F. An asymmetric total synthesis of broussonetine C. J. Carbohydr. Chem., 2003, 22(7-8), 719-732.
[http://dx.doi.org/10.1081/CAR-120026470]
[40]
Trost, B.M.; Horne, D.B.; Woltering, M.J. Palladium-catalyzed DYKAT of butadiene monoepoxide: Enantioselective total synthesis of (+)-DMDP, (-)-bulgecinine, and (+)-broussonetine G. Chemistry, 2006, 12(25), 6607-6620.
[http://dx.doi.org/10.1002/chem.200600202] [PMID: 16807949]
[41]
Ribes, C.; Falomir, E.; Murga, J.; Carda, M.; Alberto Marco, J. Convergent, stereoselective syntheses of the glycosidase inhibitors broussonetines D and M. Org. Biomol. Chem., 2009, 7(7), 1355-1360.
[http://dx.doi.org/10.1039/b821431j] [PMID: 19300820]
[42]
Ribes, C.; Falomir, E.; Murga, J.; Carda, M.; Marco, J.A. Convergent, stereoselective syntheses of the glycosidase inhibitors broussonetines C, O and P. Tetrahedron, 2009, 65(51), 10612-10616.
[http://dx.doi.org/10.1016/j.tet.2009.10.066]
[43]
Myeong, I.S.; Ham, W.H. Stereoselective syntheses of (+)-Broussonetine D and (+)-Australine via a functionalized pyrrolidine from an extended chiral 1,3-oxazine. Eur. J. Org. Chem., 2019, 2019(5), 1077-1082.
[http://dx.doi.org/10.1002/ejoc.201801552]
[44]
Kim, J.Y.; Mu, Y.; Jin, X.; Park, S.H.; Pham, V.T.; Song, D.K.; Lee, K.Y.; Ham, W.H. Efficient and stereoselective syntheses of DAB-1 and D-fagomine via chiral 1,3-oxazine. Tetrahedron, 2011, 67(48), 9426-9432.
[http://dx.doi.org/10.1016/j.tet.2011.09.084]
[45]
Holzapfel, C.W.; Crous, R. Synthesis and reactions of chiral cyclic nitrones. Heterocycles, 1998, 48, 1337-1342.
[http://dx.doi.org/10.3987/COM-98-8166]
[46]
Carmona, A.T.; Whigtman, R.H.; Robina, I.; Vogel, P. Synthesis and glycosidase inhibitory activity of 7-deoxycasuarine. Helv. Chim. Acta, 2003, 86(9), 3066-3073.
[http://dx.doi.org/10.1002/hlca.200390248]
[47]
Wennekes, T. Lipophilic Iminosugars: Synthesis and Evaluation as Inhibitors of Glucosylceramide Metabolism; Ph.D. Thesis, Leiden University, Netherlands, 2008.
[48]
Zhao, H.; Kato, A.; Sato, K.; Jia, Y.M.; Yu, C.Y. Total synthesis and glycosidase inhibition of broussonetine I and J(2). J. Org. Chem., 2013, 78(16), 7896-7902.
[http://dx.doi.org/10.1021/jo4010553] [PMID: 23829312]
[49]
Song, Y.Y.; Kinami, K.; Kato, A.; Jia, Y.M.; Li, Y.X.; Fleet, G.W.J.; Yu, C.Y. First total synthesis of (+)-broussonetine W: glycosidase inhibition of natural product & analogs. Org. Biomol. Chem., 2016, 14(22), 5157-5174.
[http://dx.doi.org/10.1039/C6OB00720A] [PMID: 27184090]
[50]
Wu, Q-K.; Kinami, K.; Kato, A.; Li, Y-X.; Fleet, G.W.J.; Yu, C.Y.; Jia, Y.M. Synthesis and glycosidase inhibition of broussonetine M and its analogues. Molecules, 2019, 24(20), 3712.
[http://dx.doi.org/10.3390/molecules24203712] [PMID: 31619020]
[51]
Li, Y.X.; Huang, M.H.; Yamashita, Y.; Kato, A.; Jia, Y.M.; Wang, W.B.; Fleet, G.W.J.; Nash, R.J.; Yu, C.Y. L-DMDP, L-homoDMDP and their C-3 fluorinated derivatives: Synthesis and glycosidase-inhibition. Org. Biomol. Chem., 2011, 9(9), 3405-3414.
[http://dx.doi.org/10.1039/c0ob01063d] [PMID: 21423946]
[52]
Tsou, E.L.; Yeh, Y.T.; Liang, P.H.; Cheng, W.C. A convenient approach toward the synthesis of enantiopure isomers of DMDP and ADMDP. Tetrahedron, 2009, 65(1), 93-100.
[http://dx.doi.org/10.1016/j.tet.2008.10.096]
[53]
Huang, M.H.; Li, Y.X.; Jia, Y.M.; Yu, C.Y. General intermediates for the synthesis of 6-C-alkylated DMDP-related natural products. Molecules, 2013, 18(6), 6723-6733.
[http://dx.doi.org/10.3390/molecules18066723] [PMID: 23749160]
[54]
Rössler, S.L.; Schreib, B.S.; Ginterseder, M.; Hamilton, J.Y.; Carreira, E.M. Total synthesis and stereochemical assignment of (+)-Broussonetine H. Org. Lett., 2017, 19(20), 5533-5536.
[http://dx.doi.org/10.1021/acs.orglett.7b02620] [PMID: 28968123]
[55]
Li, Y.X.; Shimada, Y.; Sato, K.; Kato, A.; Zhang, W.; Jia, Y.M.; Fleet, G.W.J.; Xiao, M.; Yu, C.Y. Synthesis and glycosidase inhibition of australine and its fluorinated derivatives. Org. Lett., 2015, 17(3), 716-719.
[http://dx.doi.org/10.1021/ol503728e] [PMID: 25621897]
[56]
Cheng, W.C.; Guo, C.W.; Lin, C.K.; Jiang, Y.R. Synthesis and inhibition study of bicyclic iminosugar-based alkaloids, scaffolds, and libraries towards glucosidase. Isr. J. Chem., 2015, 55(3-4), 403-411.
[http://dx.doi.org/10.1002/ijch.201400140]
[57]
Li, Y.X.; Wang, J.Z.; Kato, A.; Shimadate, Y.; Kise, M.; Jia, Y.M.; Fleet, G.W.J.; Yu, C.Y. Stereocomplementary synthesis of casuarine and its 6- epi -, 7- epi -, and 6,7-di epi -stereoisomers. Org. Biomol. Chem., 2021, 19(43), 9410-9420.
[http://dx.doi.org/10.1039/D1OB01725J] [PMID: 34668913]
[58]
Gossan, D.P.A.; Alabdul Magid, A.; Kouassi-Yao, P.A.; Behr, J.B.; Ahibo, A.C.; Djakouré, L.A.; Harakat, D.; Voutquenne-Nazabadioko, L. Glycosidase inhibitors from the roots of Glyphaea brevis. Phytochemistry, 2015, 109, 76-83.
[http://dx.doi.org/10.1016/j.phytochem.2014.10.029] [PMID: 25468536]
[59]
Hama, N.; Aoki, T.; Miwa, S.; Yamazaki, M.; Sato, T.; Chida, N. Total synthesis of broussonetine F: The orthoamide Overman rearrangement of an allylic diol. Org. Lett., 2011, 13(4), 616-619.
[http://dx.doi.org/10.1021/ol102856j] [PMID: 21194237]
[60]
Wierzejska, J.; Ohshima, M.; Inuzuka, T.; Sengoku, T.; Takahashi, M.; Yoda, H. Total synthesis and absolute stereochemistry of (+)-batzellaside B and its C8-epimer, a new class of piperidine alkaloids from the sponge Batzella sp. Tetrahedron Lett., 2011, 52(11), 1173-1175.
[http://dx.doi.org/10.1016/j.tetlet.2011.01.018]
[61]
Wierzejska, J.; Motogoe, S.; Makino, Y.; Sengoku, T.; Takahashi, M.; Yoda, H. A new approach toward the total synthesis of (+)-batzellaside B. Beilstein J. Org. Chem., 2012, 8, 1831-1838.
[http://dx.doi.org/10.3762/bjoc.8.210] [PMID: 23209519]
[62]
Okaki, T.; Fujimura, R.; Sekiguchi, M.; Zhou, D.; Sugimoto, K.; Minato, D.; Matsuya, Y.; Kato, A.; Adachi, I.; Tezuka, Y.; Saporito, R.A.; Toyooka, N. Stereoselective total synthesis of (-)-Batzellasides A, B, and C. Eur. J. Org. Chem., 2013, 2013(14), 2841-2848.
[http://dx.doi.org/10.1002/ejoc.201201567]
[63]
Petasis, N.A.; Zavialov, I.A. Highly stereocontrolled one-step synthesis of anti -β-amino alcohols from organoboronic acids, amines, and α-hydroxy aldehydes. J. Am. Chem. Soc., 1998, 120(45), 11798-11799.
[http://dx.doi.org/10.1021/ja981075u]
[64]
Pyne, S.G.; Tang, M. The Boronic Acid Mannich Reaction, Organic Reactions; Wiley, 2014, 83, pp. 211-498.
[65]
Pyne, S.G. My 37 years of working with nitrogen heterocycles and alkaloids. Aust. J. Chem., 2022, 75(11), 923-944.
[http://dx.doi.org/10.1071/CH22144]
[66]
Jiangseubchatveera, N.; Bouillon, M.E.; Liawruangrath, B.; Liawruangrath, S.; Nash, R.J.; Pyne, S.G. Concise synthesis of (−)-steviamine and analogues and their glycosidase inhibitory activities. Org. Biomol. Chem., 2013, 11(23), 3826-3833.
[http://dx.doi.org/10.1039/c3ob40374b] [PMID: 23640519]
[67]
Bouillon, M.E.; Nash, R.J.; Pyne, S.G. Studies towards the synthesis of polyhydroxylated pyrrolidine alkaloids isolated from Broussonetia kazinoki (moraceae). Tetrahedron, 2022, 128, 133104.
[http://dx.doi.org/10.1016/j.tet.2022.133104]

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