| 摘要 |
<p>PURPOSE:To obtain the titled substance in short steps, by oxidizing a compound such as methyl 5-tert-butyldimethylsilyloxy-10-hydroxy-9-methoxy-1-methyl-3, 4- dihydro-1H-naphtho[2, 3-c]pyran-3-ylacetate. CONSTITUTION:A compound of formulaI(R is lower alkyl; R<1> is H or lower alkyl; R<2> is H, alkyl or aralkyl; Z is protecting group), e.g. methyl 1-butyl-5- tert-butyldimethylsilyloxy-10-hydroxy-9-methoxy-3, 4-dihydro-1H-naphtho[2, 3-c] pyran-3-ylacetate, is oxidized in the presence of an oxidizing agent in a solvent, e.g. acetonitrile, to give a compound of formula II. The compound of formula Iis obtained by reacting a compound of formula III with a compound of formula IV (X is reactive atom, etc.), reducing the resultant compound of formula V, and cyclizing the reduction product.</p> |
