Synthesis of tachrosin, (±)-stachyoidin, and (±)-tephrodin, prenylflavonoids of novel type from Tephrosia polystachyoides
- 1 January 1977
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 9,p. 948-953
- https://doi.org/10.1039/p19770000948
Abstract
Tachrosin [8-(2,3-dihydro-2,2-dimethyl-3-oxo-4-furyl)-5,7-dimethoxyflavone](1) has been synthesized by oxidative rearrangement of a 1-aryl-4-hydroxypent-1-en-3-one with thallium(III) nitrate followed by cyclisation to a 4-aryl-2,2-dimethylfuran-3(2H)-one as the key step. A multi-stage transformation of the flavone (1) gave 8-(3-hydroxy-3-methyl-2-oxobutyl)-5-methoxy-7-methoxycarbonylmethoxyflavone (29), which afforded in one step the furo[2,3-c]pyran (30). Reduction of (30) with borohydride and reoxidation yielded (±)-stachyoidin (2), and treatment of (2) with lead tetra-acetate gave (±)-tephrodin (3). Sodium alkoxides are shown to catalyse the transacetalisation of α-aryl-α-aroylacetaldehyde acetals.This publication has 0 references indexed in Scilit: