Anthrone (1) can be alkylated selectively to give O-, C, O-or C, C-substituted compounds 2, 4, or 5, respectively. Similarly, 5, 5-dimethyl-3-isoxazolidinone (6) and 4-methylquinolone (9) yield N-or O-derivatives 7 and 8 or 10 and 11, respectively. The product ratios can be influenced strongly sometimes by use of different phase transfer catalysts, but the sensitivity of each reaction towards the catalysts is unique.
