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33. Experimental procedures: Procedure for methyl ester (Table 2): To a well-stirred
mixture of acid (80 mmol) in TBME (50 mL) was added sulfuric acid (1.8 g,
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5.5 mL) at the same temperature and maintained for 4–5 h then was allowed to
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layer was washed with water (100 mL), dried over sodium sulfate, and
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