Shikimic acid Group Meeting Narendra Ambhaikar 1/12/2005

Biosynthetic pathway

OPO3H2 HO CO H OH 2 OH OH CO2H O O phosphoenolpyruvic OH OH acid CO2H OH OH OH OH O OPO3H2 H2O3PO 3-deoxy-D-arabino- glucose H heptulosonic acid phosphate HO OH OH OH D-erythrose 4-phosphate (E4P) (-)-shikimic acid CO2H HO CO2H OH OH -Shikimic acid is a hydroaromatic intermediate in the common pathway of aromatic O OH O OH amino acid biosynthesis. OH OH 3-dehydroshikimic acid -First isolated in 1885 by Eykman from the fruit of Illicium religiosum. Found to exist 3-dehydroquinic acid widely in leaves of fruit of many plants and also in microorganisms, but in limited CO H CO H quantities. 2 2 HO CO2H

-Relative and absolute stereochemistry realized only in 1930s through the works of Fischer, Freudenberg and Karrer. HO OH H2O3PO OH HO OH OH OH OH -It is mainly involved in the biosynthetic shikimate pathway operative in plants and (-)-shikimic acid shikimate 3-phosphate (-)-quinic acid microorganisms and discovered by Davis, Sprinson and Gibson. Three amino acids (L-phenylalanine, L-tyrosine and L-tryptophan) are synthesized along the pathway. Some molecules synthesized Some molecules synthesized from (-)-shikimic acid from (-)-quinic acid H -Available commercially (from Aldrich $58.00 per gram). Limited availability from HO OBz N H plants has led to the discovery of other synthetic and biosynthetic means to obtain HO O H N N 2 N Br shikimic acid. Recently reported to be derived from microbial fermentation of glucose O CO2Et using recombinant E. coli. Used as starting material for the synthesis of drug HN H BzO O AcHN CO2Me N molecules and natural products. H zeylenone MeO HO NH2.H3PO4 O N -There is great potential for the design and synthesis of enzyme inhibitors which may oseltamivir phosphate H selectively block specific enzyme-catalysed transformations along this pathway. HO OH dragmacidin F (Stoltz) OH OH OH pericosine B (Usami) CO2H OMe HO N References on recombinant microbial catalysis: 1) Draths, K. M.; Knop, D. R.; Frost, J. W. J. O NH MeO N Am. Chem. Soc.1999, 121, 1603. 2) Knop, D. R.; Draths, K. M.; Chandran, S. S.; Barker, J. 1α,dihydroxy-19-norprevitamin D3 H H H L.; von Daeniken, R.; Weber, W.; Frost, J. W. J. Am. Chem. Soc. 2001, 123, 10173. OH OH Leuenberger, H. G. W.; Matzinger, P. K.; Wirz, B. Chimia 1999, 53, 536. OH H HO OH OH MeO2C OR Reviews mycosporin-gly ii) Bohm, B. A. Chem. Rev. 1965, 65, 435. (-)-MK7607 (White) HO OH OMe ii)Campbell, M. M.; Sainsbury, M.; Searle, P. A.. Synthesis 1993, 179. HO OH OH (-)-reserpine iii) Jiang, S.; Singh, G. Tetrahedron 1998, 54, 4697. OH (+)-proto-quercitol (Hanessian) (Shih) Shikimic acid Group Meeting Narendra Ambhaikar 1/12/2005

SYNTHESIS OF SHIKIMIC ACID CO2Me CO2Me CO2Me CO2Me CO2Me CO2Me - Several syntheses have been reported. The following discussion will cover some of them. Br i) AgOAc, AcOH OH OH + H2O + + + Br OAc OAc ii) MeOH, HCl HO OAc HO OAc OAc OAc Synthesis of shikimic acid via Diels Alder reaction OAc OAc OAc OAc OAc OAc KOH, MeOH,H2O Raphael (1960) and Smissman (1959) - identical routes 20% 5% 1% 7% CO2H OAc OAc OAc OAc

CO2H HO CO2Me O CO2Me CO2H hydroquinone OsO , Et O HO OH + 85-90 oC 4 2 HCl Py, CH2N2 HO acetone O OH OAc OAc OAc OAc (±)-shikimic acid 11% overall yield

CO2H Grewe, R.; Hinrichs, I. Chem. Ber. 1964, 97, 443.

o O CO2Me HO CO2H MgO, 290 C i) Ac2O, Py H2O, AcOH ii) (-)-quinine, MeOH iii) KOH, MeOH-H2O Koreeda (1982) O KOH, MeOH-H2O HO HO OH OAc OAc OH OAc OAc OAc OAc (−)-shikimic acid CO Me CO2Me HO CO2Me 2 HO CO Me 15% overall yield xylenes OsO , NMO 2 + (72%) 4 p-TsOH H2O (96%) McCrindle, R.; Overton, K. H.; Raphael, R. A. J. Chem. Soc. 1960, 1560. HO PhH (98%) Smissman, E. E.; Suh, J. T.; Oxman, M.; Deniels, R. J. Am. Chem. Soc. 1959, 81, 2909. SiMe3 SiMe3 SiMe3

OAc OAc CO2Me Smissman (1968) MCPBA i) HCl, MeOH HO CO2Me i) LiOH, THF-H2O AcO (91%) ii) Ac2O, Py CO2H ii) Ac2O, Py O O O O iii) DBU, THF PhH, heat OsO4, H2O2 HO H O, rt, 3 d HO AcO (54%) 2 65% AcO OAc + (67%) O O O O (66%) O O 71% O O OAc HO HO O (±)-shikimic acid OAc O OAc O OAc O OAc 29% overall yield 2-acetoxyfuran ketoacid Koreeda's 2nd generation synthesis employing Fleming oxidation O CO Me CO H OAc OAc O OAc O 2 i) soft glass powder 2 O hydroquinone i) NaBH i) MeOH, HCl TMS HO TMS 4 AcO AcO sealed tube, vac TMS monomethyl O O ii) Ac2O ii) Ac2O (57%) o ether (cat.), 256 - 258 C (92%) + O OsO , NMO xylenes (77%) 4 O ii) saponification (75%) (96%) OAc AcO OAc HO OH HO OAc OAc OH SiMe2Ph SiMe2Ph SiMe2Ph (±)-shikimic acid 3% overall yield OAc O O CO2H KBr , AcOOH HO TMS HO TMS AcOH, NaOAC O DBU, THF O Grewe (1964) (81%) (94%) n-Bu4NF HO HO (98%) HO OH CO2H i) hydroquinone CO2Me CO2Me toluene, 130 -140 oC i) AcOH, H2O2 then OH OH OH H O (85%) + (85%) 2 NBS, CCl4 ii) Ac O, Py (80%) (±)-shikimic acid 2 Koreeda, M.; Ciufolini, M. A. J. Am. Chem. Soc. 1982, 104, 2308. 55% overall yield ii) MeOH, c. H2SO4 OAc (97%) Koreeda, M.; Teng, K.; Murata, T. Tetrahedron Lett. 1990, 31, 5997. OAc Narendra Ambhaikar Shikimic acid Group Meeting 1/12/2005

From benzene (Birch, 1988) APPLICATIONS OF (-)-SHIKIMIC ACID IN SYNTHESIS

(-)-zeylenone HO OBz CO H CO H - + - + 2 2 CO2 Ph NH3 CO2 Ph NH3 HO O Ph NH2 i) Me2SO4, KOH Me H Me H M Me H M +M BzO ii) Fe(CO)5, n-Bu2O iii) c. H2SO4 CHCl3-acetone - a polyoxygenated cyclohexene showing antiviral, anticancer and antibiotic activities isolated racemic complex mixture subjected to resolution from Uvaria grandiflora

- + CO2 Ph NH3 CO2Me CO2Me CO2Me

Ph3PF6 Me H i) aq. HCl, EtOH hexane NaHCO3, H2O Enantioselective synthesis of zeylenone from (-)-shikimic acid M M M + - ii) CH2N2, Et2O CH2Cl2 PF6 MeCN (95%) M (73%) OH 100% CSA, MeOH CO2 Me CO2 Me CO2Me CO2Me CO2Me CO2 Me CO2 Me i) TBDMSCl (MeCO)2 i-Pr2NEt (98%) TBDMSCl ii) Me NO (84%) OsO4 (67%) TBAF (85%) CH(OMe)3 + 3 CSA (93%) Im, DMAP O OH HO O (97%) OTBDMS HO OTBDMS HO OH HO OH TBDMSO O O O OH OH OH MeO O OMe (−)-methyl shikimate OMe OMe (-)-methyl shikimate OMe 10% 83% OMe M = Fe(CO)3, provides lateral control for enantiospecifically installing the hydroxy group CH OBz Birch, A. J.; Kelly, L. F.; Weerasuria, D. V.; J. Org. Chem. 1988, 53, 278. 2 O CH2OBz i) DIBAL-H (92%) i) OsO4, NMO (94%) O ii) BzCl, DMAP ii) Me2C(OMe)2, TsOH Py (97%) (99%) TFA/H O (1:1) Palladium mediated elimination reaction (Ogasawara, 2000) TBDMSO O 2 TBDMSO O (79%) CO2Me CO2Me CO2Me O OH OAc O i) TBSCl, Im, DMF OMe OMe OMe ii) AcCl, TEA, DMAP PdCl (PPh ) (cat.) 2 3 2 30% H2O2 OMe (81%) HCO2NH4, MeCN (79%) Triton B (75%) iii) TBAF, THF (80%)

O O CH OBz O CH2OBz HO HO O CH2OBz 2 O O O CO2Me CO2Me CO2Me TBAF Ph3P, Im i) NaBH NaOH- I (87%) PhCO2H 4 2 (94%) BzCl, DMAP MeOH(79%) Ph O, 280 oC TBDMSO OH TBDMSO HO Py (99%) ii) BzCl, BuNCl,NaOH 2 BF3.OEt2 O toluene (59%) O BzO OH O cyclohexene O BzO HO CH2OBz exo-epoxide CH OBz CH OBz CO Me O 2 O 2 O 2 CO Me SeO2, THF HO 2 O (40%) O O TFA/H2O (9:1) CO2Me (85%)

i) K2CO3, MeOH (72%) BzO ii) KOH, THF BzO BzO OBF O 3 HO OH (+)-zeylenone:CD spectra O BzO OH indicated (+)-antipode of the OH natural product OH Ph (−)-shikimic acid Yoshida, N.; Ogasawara, K. Org. Lett. 2000, 2, 1461. Liu, A.; Liu, Z. Z.; Zou, Z. M.; Chen, S. Z.; Xu, L. Z.; Yang, S. L. Tetrahedron, 2004, 60, 3689. Narendra Ambhaikar Shikimic acid Group Meeting 1/12/2005

Chiral syntheses of (-)-shikimic acid

From carbohydrates CO2Me CO2Me CO2Me CO2Me HO HO SO2Cl2, Py -70 oC (78%) NaOMe O BzCl, Py (85%) OR MeOH OH O HO OH O BzO OBz BzO OBz HO OH HO acetone O OBn HO OH POCl , Py (75%) O c. H SO i) BnCl, NaH, DMF HO 3 2 4 OH OBz OBz OH (cat.) ii) c. HCl, MeOH, H2O NaIO4, H2O, rt OH OO HO OO (-)-methyl quinate (-)-methyl shikimate OH D-mannose O Cleophax, J.; Mercier, D.; Gero, S. D. Angew. Chem. Int. Ed. Engl. 1971, 10, 652. OBn O OBn O Cleophax, J.; Leboul, J.; Mercier, D.; Gaudemer, A.; Gero, S. D. Bull. Soc. Chim. Fr. 1973, 2992. OHC OBn HO F3CO2CSO (CF3SO2)2O o NaBH4, EtOH Py, CH2Cl2, -30 C OO 100% OO OO

CO2Me lyxo-alcohol HO HO CO2Me (66% from D-mannose) HO CO2H CO t-Bu O OBn 2 CO2H butan-2,3-dione TBSOTf (MeO)2OP (MeO) CH, CSA HO O Et3N (97%) NaH i) Pd-C (10%), 3 TBSO O MeOH, D (79%) OMe (MeO)2OPCH2CO2t-Bu MeOH, H2 HO OH OMe t-BuO2C aq. TFA (100%) O O DMF, 15-crown-5 (81%) OOii) NaH, THF (73%, OH Me two steps) MeO Me O OH HO OH MeO (-)-quinic acid Me Me O OH butane diacetal (-)-shikimic acid 10 steps, 39% overall yield CO2Me CO2Me CO Me Fleet, G. W. J.; Shing, T. K. M.; Warr, S. M. J. Chem. Soc. Perkin Trans. I, 1984, 905. 2

+ TBSO O TBSO O TFA, H2O Martin's sulfurane OMe rt CH Cl , rt (83%) OMe O 2 2 O Me HO OH From (-)-quinic acid Me MeO MeO Me OH Me (-)-methyl shikimate - several synthesis of (-)-shikimic acid from (-)-quinic acid have been published A A:B 30:1 B - (-)quinic acid is found in Cinchona bark and more readily available (available from Aldrich $110.50 / 100g) than (-)-shikimic acid

Box, J. M.; Harwood, L. M.; Humphreys, J. L.; Morris, G. A.; Redon, P. M.; Whitehead, R. C. Synlett CO NH CN CO H CO2H HO CO2H HO 2 2 2 2002, 2, 358.

p-TsCl, Py aq. NaOH aq. H2SO4 37 oC, 7 days reflux 2.5 h reflux OAc HO OH O O OAc O OH HO OH OH O O O OH (-)-quinic acid (-)-shikimic acid

Dangschat, G.; Fischer, H. O. L. Naturwissenschaften 1938, 26, 562. Dangschat, G.; Fischer, H. O. L. Biochim. Biophys. Acta 1950, 4, 199. Shikimic acid Group Meeting Narendra Ambhaikar 1/12/2005

1α,dihydroxy-19-norprevitamin D3 Synthesis of (-)-MK7607 and other carbasugars

OH OAc OAc OH OH OH OH OAc

HO HO OH HO OH AcO OAc OH OH OAc - an analogue of the hormone 1α,25-dihydroxyvitamin D3 (-)-MK7607 gabosine K pentaacetate of carba-β- D-altropyranose

OMOM OMOM - carbasuguars or pseudosugars lack the acetal function which is characteristic of LDA, THF, -78 oC common monosaccharades PhNTf2 (89%) - known to display a range of biological activities, particular as glycosidase H H O OTf inhibitors

known compound derived from vinyl triflate CO H CO Me CO Me vitamin D2 2 2 2 i) CSA, MeOH (96%) Tf O, DMAP, Py ii) CSA, Me2C(OMe)2 (95%) 2 CO2H CO2Me CH2OH CH2Cl2 (98%) i) MeOH, HCl (cat.) HO OH O OH O OTf (98%) ii) TBSCl, TEA i) PhOC(S)Cl, DMAP (93%) OH O O DMAP (82%) ii) DIBAL-H (86%) HO OH TBSO OTBS TBSO OTBS OH OH O S CO2Me CO2Me HO CO2Me OPh OH HO CsOAc, DMF (81%) OsO4, NMO + (-)-shikimic acid CH2OH CHO O O OH O n-Bu3SnH i) Zn, Ph3P, CBr4 AIBN (cat.) Py (93%) O O O (63%) MnO2 (82%) ii) n-BuLi (80%) TBSO OTBS TBSO OTBS A(38%) B (35%) Name reaction Name reaction TBSO OTBS enyne OH OH OH CO2Me OH Me C(OMe) , CSA O O 2 2 DIBALH vinyl triflate (98%) TFA-H2O OH A (99%) (92%) OH O O (Ph P) PdCl O HO OH + 3 2 2 i) H2, Lindlar's catalyst O TEA, DMF, 75 oC quinoline O O OH ii) TBAF, THF enyne 85% 80% HO (-)-MK7607 TBSO OTBS 1α,dihydroxy-19-norprevitamin D3 17% overall yield, 11 steps

Sarandeses, L. A.; Mascerenas, J. L.; Castedo, L.; Mourino, A. Tetrehedron Lett. 1992, 33, 5445. Song, C.; Jiang, S.; Singh, G. Synlett 2001, 12, 1983. Shikimic acid Group Meeting Narendra Ambhaikar 1/12/2005

Kilogram scale synthesis of Oseltamivir phosphate (Tamiflu) Roche-Basel Route to oseltamivir phosphate (azide free synthesis)

O CO2Et O CO2H

AcHN AcHN O CO Et 2 O CO Et NH2.H3PO4 NH2 i) MgBr2.OEt2 (0.2 equiv.) 2 i) Pd/C, EtOH t-BuOMe/MeCN 9:1 O CO Et H2N(CH2)2OH 2 GS-4104 GS-4071 55 oC, 16h reflux ii) (NH ) SO /H O O 4 2 4 2 HO ii) H2SO4/H2O HO + HN 97% 77% NH -it is a prodrug of the potent and selective competitive inhibitor (GS-4071) of influenza A and B NH2 2 neuraminidase

-research and development by Gilead Sciences Inc. and F. Hoffmann-La Roche Ltd. O CO Et i) PhCHO, tBuOMe, -H2O 2 O CO2Et ii) MsCl, Et3N Ac2O, AcOH, MsOH iii) allyl amine, 112 oC, 15 h o iv) HCl/H O t-BuOMe, 15 h, 20 C 2 H2N AcHN CO2Et i) EtOH, SOCl 80% HN HN 2 CO Et CO Et 83% ii) 3-pentanone, TsOH O 2 TMSOTf O 2 iii) MsCl, Et3N BH3.Me2S

HO OH 80% O 63-75% HO OH OMs OMs i) Pd/C, EtOH H2NCH2CH2OH (-)-shikimic acid major product reflux O CO Et ii) H3PO4, EtOH 2

70% AcHN KHCO , aq. EtOH O CO2Et O CO2Et O CO2Et 3 NH2.H3PO4 96% NaN3, NH4Cl aq. EtOH (86%) + HO N3 Oseltamivir phosphate in O N OH 35-38% overall yield from 3 the epoxide ABA:B 10:1

Me3P O CO2Et O CO2Et O CO Et i) NaN3, NH4Cl 2 (97%) i) Ra-Ni, H2 DMF (44%) EtOH ii) Ac2O ii) 85% H PO AcHN 3 4 AcHN HN N (71-75%) aziridine (74% purity) 3 NH2 Karpf, M.; Trussardi, R. J. Org. Chem. 2001, 66, 2044. 21% overall yield in 10 steps from (-)-shikimic acid

1. Kim, C. U.; Lew, W.; Williams, M. A.; Liu, H.; Zhang, L.; Swaminathan, S.; Bischofberger, N.; Chen, M. S.; Mendel, D. B.; Tai, C. Y.; Laver, G.; Stevens, R. C. J. Am. Chem. Soc. 1997, 119, 681. 2. Rohloff, J. C.; Kent, K. M.; Postich, M. J.; Becker, M. W.; Chapman, H. H.; Kelly, D. E.; Lew, W.; Louie, M.S.; McGee, L. R.; Prisbe, E. J.; Shultze, L. M.; Yu, R. H.; Zhang, L. J. Org. Chem. 1998, 63, 4545. Narendra Ambhaikar Shikimic acid Group Meeting 1/12/2005

Industrial synthesis of oseltimivir phosphate (50-250 kg)

HO CO2H HO CO Et i) EtOH, SOCl 2 CO2Et 2 i) Me2C(OMe)2 (2.0eq) O reflux HO TsOH (0.01 eq) ii) evaporation EtOAc, OH HO ii) evaporation O 97% OH 95% OH (-)-shikimic acid i) MsCl (1.3 eq) ii) Et3N (2.0 eq) EtOAc, 0-5 oC iii) filtration O CO2Et i) pentanone (15 eq) CO Et iv) evaporation CF3SO3H (0.045 eq) O 2 v) cryst. MeOH ii)extraction O iii) evaporation O 89% OMs 98% OMs

i) Et3SiH (1.3 eq) CO Et CO2Et CO2Et TiCl4 (1.1 eq) O 2 HO HO -6 CH2Cl2, -34 oC, 2 h ii) poured on H2O HO + O + HO extr.NaHCO3 OMs OMs OMs

regioisomers 32:1 2-4%

i) NaHCO3 (1.6 eq) EtOH/H2O, 60 oC, 1.5 h ii) extr. n-hexane CO Et iii) cryst n-hexane O 2

O CO2Et O

80% from pentylidnene ketal, AcHN 63-65% from (-)-shikimic acid in NH .H PO 6 steps 2 3 4 assay HPLC > 98%

Federspiel, M. et al. Org. Proc. Res. Dev. 1999, 3, 266.