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In acetone; |
(1) A mixture of 9-bromoacetyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione (1.00 g) obtained in Reference Example 1-(1), <strong>[6106-41-8]sodium valerate</strong> (1.44 g) and acetone (50 ml) was stirred under reflux for 5 hours, cooled to room temperature and concentrated under reduced pressure. The residue was triturated with an adequate quantity of ether, and solid substances were filtered to give reddish crystals of 9-valeryloxyacetyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione. M.P., 170°-172° C. IR (Nujol) nucm-1: 3400, 1775, 1770, 1620, 1585. NMR (CDCl3) delta: 0.83-3.15 (m, 16H), 5.12 (bs, 2H), 7.80 (m, 2H), 8.30 (m, 2H), 13.37 (bs, 2H). |
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In acetone; |
(1) A mixture of 9(R)-bromoacetyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione (1.00 g) obtained in Reference Example 4-(1), <strong>[6106-41-8]sodium valerate</strong> (1.44 g) and acetone (50 ml) was stirred under reflux for 2 hours. After removing insoluble matters by filtration, the reaction mixture was concentrated under reduced pressure. The residue was treated with ether (15 ml) and precipitated crystals were collected by filtration to give orange crystals of 9(R)-valeryloxyacetyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione. M.P., 149°-152° C. IR (Nujol) nucm-1: 1730, 1620, 1585. NMR (CDCl3) delta: 1.93 (t, J=6 Hz, 3H), 1.16-2.30 (m, 6H), 2.32-2.63 (m, 2H), 2.93 (bs, 4H), 5.20 (s, 2H), 7.60-7.87 (m, 2H), 8.00-8.26 (m, 2H). |