Total synthesis of (.+-.)-methyl shikimate and (.+-.)-3-phosphoshikimic acid

Bartlett, Paul A.; McQuaid, Loretta A.

doi:10.1021/ja00337a035

Cited by 59 publications

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“…The 1 H NMR spectrum showed the expected number and patterns of signals consistent with that structure, mainly the signals at δ ϭ 3.65 (methyl ester) and 9.82 ppm (formyl group) replacing the olefinic protons, and the fact that the formyl proton is a singlet indicates that the carbon atom of the formyl group is attached to a quaternary carbon atom, as in structure 6. Accordingly, its 13 C NMR spectrum displays two peaks at δ ϭ 172.55 and 205.78 ppm as expected for the two carbonyl groups, ester and formyl functionality, together with the methoxy group signal at δ ϭ 51.77 ppm. The peaks corresponding to the carbon atoms involved in the acetal unit were shifted downfield, and the quaternary carbon atom β to the formyl group was shifted downfield to δ ϭ 36.10 ppm with respect to the corresponding signal at δ ϭ 31.12 ppm in olefinic acetal 10.…”

Section: Resultsmentioning

confidence: 62%

“…This transformation is clearly shown by the 1 H NMR upfield shift of the formyl proton signal from δ ϭ 9.82 to δ ϭ 8.46, a characteristic value for a formate, as well as the 13 C NMR carbonyl shift from δ ϭ 205.78 to δ ϭ 159.86 ppm. It is also indicated by the downfield shift of the newly formed acetalic carbon atom going from δ ϭ 82.78 ppm to δ ϭ 106.89 ppm.…”

Section: Resultsmentioning

confidence: 97%

“…As outlined in Scheme 3, the synthesis began with selenium dioxide elimination [13,14] from the selenide 7, [9,15,16] followed by oxidative rearrangement [17] of the allylic alcohol 8 by treatment with pyridinium chlorochromate. This gave rise to the α,β-unsaturated ketone 9, which was isolated pure in good yield (92%).…”

Section: Resultsmentioning

confidence: 99%

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Synthesis of the Tetracyclic Bis(acetal) Lactone Portion of Saudin

et al. 2003

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Section: Resultsmentioning

confidence: 62%

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confidence: 97%

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Synthesis of the Tetracyclic Bis(acetal) Lactone Portion of Saudin

et al. 2003

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“…Eneffet, si l'importance de l'acide shikimique et des dCrivCs ou analogues phosphor& est bien Ctablie et largement CtudiCe (7,8), le r6le de l'acide quinique reste ma1 connu.…”

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Étude conformationnelle et structurale de 1,5-diacétoxy-3,4-bis(bicyclophosphoranylato)quinate de méthyle

Baltas¹,

Chahoua²,

Gorrichon³

et al. 1991

Can. J. Chem.

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In connection with our work on quinic acid derivatives, which are supposed to regulate the biosynthesis of aromatic amino acids, we have prepared the methyl 1,5-di-O-acetyl-3,4-bis-O-(bicyclophosphoranylato)quinate 7. The compound obtained has been characterized by NMR (1H and 31P), IR, elemental analysis, and mass spectrometry. Its molecular structure has been determined by X-ray diffraction and an exhaustive conformational study has been accomplished. The quinic ring adopts an almost perfect chair form. Both bicyclophosphoranyl groups present a trigonal bipyramidal geometry with an axial–equatorial–axial type annelation. The pentagonal rings adopt an envelope form in which the tetrasubstituted carbon atom is at the top of the fold. Key words: shikimic acid pathway, methyl 1,5-di-O-acetyl-3,4-bis-O-(bicyclophosphoranylato)quinate, conformational analysis, 1H and 31PNMR, crystal structure.

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“…In fact, the diselenide 7 was obtained with a yield of 72% by reaction of the diol 6 with 4.8 equivalents of o-nitrophenylselenocyanate-tri-n-butylphosphine in THF-pyridine. Diselenide 7 was subjected to various simultaneous oxidation-elimination and epoxidation procedures with epoxidizing reagents such as sodium perborate/acetic anhydride (13), p-nitroperoxybenzoic acid (1 4), trifluoroacetic anhydride/ H202 (15), and trichloroacetonitrile/H~ (16) at temperatures between 0 and 4°C and for long reaction times (7 days), which yielded mainly the divinyl compound 4. However, the use of hexafluoroacetone/H202 (17) under identical reaction conditions provided the 1,2-epoxide 9 with a yield of 25%, together with the 3,4-epoxide 10 (19%) and the divinyl compound 4 (34%), while shorter reaction times and room temperature conditions yielded preferentially the 3,4-epoxide 10.…”

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Synthesis of torrentin, dihydrosantamarine, and saussurea lactone from santonin

Blay¹,

Cardona²,

Garcı́a³

et al. 1992

Can. J. Chem.

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. 70, 817 (1992).The synthesis of the eudesmanolide torrentin ( I ) by sensitized photooxygenation of synthetic dihydrosantamarine (3) is reported. Both dihydrosantamarine and dihydroreynosin (11) were obtained from the 1,2-epoxide 9, which, in turn, was prepared from the diselenide 7. An improved procedure for the synthesis of the elemanolide saussurea lactone (4) is also reported.Key words: eudesmanolide, elemanolide, santonin, torrentin, saussurea lactone.GONZALO BLAY, LUZ CARDONA, BEGONA GARC~A et JOSE R. PEDRO. Can. J. Chem. 70, 817 (1992) On rapporte la synthkse de I'eudesmolide de torrentine (1) par une photo-oxygtnation de la dihydrosantamarine de synthkse (3). On a obtenu a la fois la dihydrosantamarine et la dihydroreynosine (11) Torrentin is an eudesmanolide isolated a few years ago ( I ) procedure for the synthesis of saussurea lactone (4) from from Artemisia herba-alba subsp. vulentina, and whose santonin (2). The sesquiterpene lactones, which constitute structure has been revised recently (2). This paper reports on an important group of natural compounds widely distribthe synthesis of torrentin (1) from santonin (2) via a multiuted in the family Compositae, have received much attenstep reaction sequence involving dihydrosantamarine (3) as tion because of their biological activities (3). an intermediate product. It also contributes an improved Dihydrosantamarine (3) was synthesized previously (4) from the dihydrocostunolide (5) and, more recently, by an 1 1-step refunctionalization ( 5 ) of the A ring of santonin (2). We synthesized dihydrosantamarine (3) via a shorter synthetic pathway by applying a new selective transformation of diselenide 7 to the 1,2-epoxide 9. The conversion of dihydrosantamarine (3) into torrentin (1) involved the sensitized photooxygenation of the 3,4-double bond of the former as a key step (6).We used the diol-lactone 6 as starting product, which was prepared from santonin (2) according to Grieco ( 7 ) , i.e., by '~u t h o r to whom correspondence may be addressed. Rinled In Canadahydrogenation and epimerization (8) at C4, formation of the corresponding tosylhydrazone and a Shapiro reaction (9), and, finally, the ozonolysis of the 2,3-double bond followed by reduction with sodium borohydride. Our strategy was based on the synthesis of the 1,2-epoxide 9 from the diol6 by oxidation-elimination of the diselenide 7 and the simultaneous epoxidation of the resulting double bond. Inasmuch as the elimination of the C2 selenoxide should be faster (10) than that of the C3 selenoxide, the yield of epoxide 9 must be more favourable than that of 10 in relation to those obtained by epoxidation (3) of saussurea lactone (4).With the above ideas in mind, we addressed the synthesis Can. J. Chem. Downloaded from www.nrcresearchpress.com by 54.245.13.81 on 05/11/18For personal use only.

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Total synthesis of (.+-.)-methyl shikimate and (.+-.)-3-phosphoshikimic acid

Cited by 59 publications

References 0 publications

Synthesis of the Tetracyclic Bis(acetal) Lactone Portion of Saudin

Synthesis of the Tetracyclic Bis(acetal) Lactone Portion of Saudin

Étude conformationnelle et structurale de 1,5-diacétoxy-3,4-bis(bicyclophosphoranylato)quinate de méthyle

Synthesis of torrentin, dihydrosantamarine, and saussurea lactone from santonin

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