Abstract
Enantiomeric tetrahydrofuro[2,3-b]benzofurans, representing the ABC tricyclic portion of aflatoxins B1, B2, G1, and G2, were generated from the oxaza-Cope rearrangement of a suitably functionalized O-aryloxime. The O-aryloxime was, in turn, made from the condensation of an enantiomerically pure aldehyde derived from glutamic acid and a substituted phenoxyamine. High regioselectivity with respect to the A-ring substituents of the ABC tricycle was achieved through the use of electrochemistry. The regioselective electrochemical cleavage of 4,6-bis(tosyloxy)-2-(methoxycarbonyl)-2,3,3a,8a-tetrahydrofuro[2,3-b]benzofuran (22) resulted in a 97/3 mixture of regioisomeric phenols. The regiochemical assignments of the resulting phenols were determined by 2D NOESY NMR. The enantiomeric ratio of the final product was determined to be 96/4 by NMR analysis of diastereomers resulting from the coupling of 31a to (+)- and (±)-phenethylamine.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3775-3782 |
| Number of pages | 8 |
| Journal | Journal of Organic Chemistry |
| Volume | 59 |
| Issue number | 14 |
| State | Published - 1994 |
| Externally published | Yes |
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- Organic Chemistry
Cite this
Synthesis of the enantiomeric furobenzofurans, late precursors for the synthesis of (+)- and (-)-aflatoxins B1, B2, G1, and G2. / Civitello, Edgar R; Rapoport, Henry.
In: Journal of Organic Chemistry, Vol. 59, No. 14, 1994, p. 3775-3782.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis of the enantiomeric furobenzofurans, late precursors for the synthesis of (+)- and (-)-aflatoxins B1, B2, G1, and G2
AU - Civitello, Edgar R
AU - Rapoport, Henry
PY - 1994
Y1 - 1994
N2 - Enantiomeric tetrahydrofuro[2,3-b]benzofurans, representing the ABC tricyclic portion of aflatoxins B1, B2, G1, and G2, were generated from the oxaza-Cope rearrangement of a suitably functionalized O-aryloxime. The O-aryloxime was, in turn, made from the condensation of an enantiomerically pure aldehyde derived from glutamic acid and a substituted phenoxyamine. High regioselectivity with respect to the A-ring substituents of the ABC tricycle was achieved through the use of electrochemistry. The regioselective electrochemical cleavage of 4,6-bis(tosyloxy)-2-(methoxycarbonyl)-2,3,3a,8a-tetrahydrofuro[2,3-b]benzofuran (22) resulted in a 97/3 mixture of regioisomeric phenols. The regiochemical assignments of the resulting phenols were determined by 2D NOESY NMR. The enantiomeric ratio of the final product was determined to be 96/4 by NMR analysis of diastereomers resulting from the coupling of 31a to (+)- and (±)-phenethylamine.
AB - Enantiomeric tetrahydrofuro[2,3-b]benzofurans, representing the ABC tricyclic portion of aflatoxins B1, B2, G1, and G2, were generated from the oxaza-Cope rearrangement of a suitably functionalized O-aryloxime. The O-aryloxime was, in turn, made from the condensation of an enantiomerically pure aldehyde derived from glutamic acid and a substituted phenoxyamine. High regioselectivity with respect to the A-ring substituents of the ABC tricycle was achieved through the use of electrochemistry. The regioselective electrochemical cleavage of 4,6-bis(tosyloxy)-2-(methoxycarbonyl)-2,3,3a,8a-tetrahydrofuro[2,3-b]benzofuran (22) resulted in a 97/3 mixture of regioisomeric phenols. The regiochemical assignments of the resulting phenols were determined by 2D NOESY NMR. The enantiomeric ratio of the final product was determined to be 96/4 by NMR analysis of diastereomers resulting from the coupling of 31a to (+)- and (±)-phenethylamine.
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UR - http://www.scopus.com/inward/citedby.url?scp=0000209610&partnerID=8YFLogxK
M3 - Article
VL - 59
SP - 3775
EP - 3782
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 14
ER -