J. Demyttenaere, Stijn Vervisch, S. Debenedetti
Jul 13, 2004
Citations
1
Influential Citations
4
Citations
Journal
Synthesis
Abstract
The synthesis of a number of naturally occurring cou- marins from Pterocaulon virgatum (L.) and Conyza obscura DC is described for the first time. It concerns the synthesis of 7-(2-hy- droxy-3-methoxy-3-methylbutoxy)-6-methoxycoumarin (virgatol, 1), 7-(2-hydroxy-3-methyl-3-butenyloxy)-6-methoxycoumarin (virgatenol, 2) and 7-(2,3-epoxy-3-methylbutoxy)-6-methoxycou- marin (3). In addition, a straightforward synthesis of scopoletin (4) (7-hydroxy-6-methoxycoumarin) is reported and the synthesis of a new coumarin derivative, 6-methoxy-7-(2-oxo-3-methylbu- toxy)coumarin (7), is described. An important classification of the numerous coumarins is based on an arbitrary but biogenetically related system of the number of nuclear oxygen atoms. Thus coumarins are commonly subdivided in classes depending on their oxy- genation pattern. 7-(2-Hydroxy-3-methoxy-3-methylbu- toxy)-6-methoxycoumarin (virgatol, 1), 7-(2-hydroxy-3- methyl-3-butenyloxy)-6-methoxycoumarin (virgatenol, 2) and 7-(2,3-epoxy-3-methylbutoxy)-6-methoxycou- marin (3) are examples of dioxygenated coumarins de- rived from scopoletin (4) (Figure 1). The absolute optical configuration of substances 1-3 is not known.