A RAPID ACCESS TO HYDROXYLATED BENZ[A]ANTHRAQUINONES - HYPERVALENT IODINE OXIDATION OF BETA-NAPHTHOLS

摘要

Anionic annulation of phthalide sulfones 3 with quinone monoketals 6, accessible by phenyliodonium diacetate oxidation of naphthols 5, offers a high yielding regiospecific entry to benz[a]anthraquinones 8. Similar annulation of cyanophthalide 13 with 12, followed by photooxygenation of 14 results in a complementary route to the basic skeleton 15 of nonaromatic A-ring angucyclines. (C) 1997, Published by Elsevier Science Ltd. [References: 27]