Claisen rearrangement of 1-hydroxy-3-(3-methylbut-2-enyloxy)xanthones
- 1 January 1974
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- p. 329-333
- https://doi.org/10.1039/p19740000329
Abstract
Claisen rearrangements of 1-hydroxy-3-(3-methylbut-2-enyloxy)xanthone (6a) and its 7-methoxy-(6b) and 6-methoxy-(6c) derivatives at 200–210°in vacuo yield mixtures of the corresponding dealkenylated xanthones (7a–c), angularly condensed 4,4,5-trimethyl-4,5-dihydrofuro-derivatives (8a–c), and their linear isomers (9a–c). These results show that normal Claisen rearrangement occurs in both the available ortho-positions, viz. 2 and 4, and is followed by spontaneous cyclisation to give linearly and angularly condensed dihydrofuro-derivatives. However, 1-hydroxy-5-methoxy-(3-methylbut-2-enyloxy)xanthone (6d) afford, besides the dealkenylated xanthone (7d), only linearly condensed dihydrofuroxanthones (9d) and (14).Keywords
This publication has 0 references indexed in Scilit: