90361-87-8Relevant articles and documents
OXYGEN HETEROCYCLES BY SULPHUR YLIDE ANNULATION. IX. 3,4-DIHYDRO-2-HYDROXYMETHYL-2H,5H-PYRANOBENZOPYRAN-5-ONES FROM 3-(3-OXOALKYL)-4-HYDROXYCOUMARINS AND DIMETHYLSULPHOXONIUM METHYLIDE
Bravo, Pierfrancesco,Resnati, Giuseppe,Ticozzi, Calimero,Arnone, Alberto,Cavicchio, Giancarlo
, p. 501 - 510 (2007/10/02)
Several 3-(3-oxoalkyl)-4-hydroxycoumarins have been synthesized from the corresponding 4-hydroxycoumarins and they have been reacted with dimethylsulphoxonium methylide.Transfer of one methylene group to the carbonyl function takes place and the regio- and site-selective opening of the so formed epoxide by action of the oxygen in position 4 of the coumarin moiety gives 3,4-dihydro-2-hydroxymethyl-2H,5H-pyranobenzopyran-5-ones in medium to high yields.A full spectral characterization of twenty new products has been made, and a discussion on the different factors controlling the reaction mechanism is also reported.