Total synthesis of puerarin, an isoflavone C-glycoside

• Published in: Tetrahedron letters Vol. 44; no. 36; pp. 6857 - 6859
• Main Authors: Lee, David Y.W., Zhang, Wu-Yan, Karnati, Vishnu Vardhan R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-09-2003
• Subjects: isoflavone C-glycoside; natural product; puerarin; total synthesis; puerarin; total synthesis; isoflavone C-glycoside; natural product
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/S0040-4039(03)01715-5

We completed the first total synthesis of puerarin (
1
), an isoflavone
C-glycoside. The key intermediate, β-
d-glucopyranosyl-2,6-dimethoxybenzene (
9
), was obtained by coupling of a lithiated aromatic reagent (
3
) with pyranolactone (
2
) in 56% yield. Condensation of (
16
) with
p-methoxybenzaldehyde gave the chalcone (
17
). The protected chalcone (
18
) was cyclized to (
19
) in the presence of Tl(NO
3)
3. Demethylation of (
19
) was accomplished by refluxing with TMSI in CH
3CN to give puerarin (
1
).
The first total stereospecific synthesis of puerarin has been achieved.