(3R,3aR,4S,4aR,8aR,9aR)-Dodecahydro-3-methyl-1,7-dioxo-naphtho[2,3-c]furan-4-carboxylic acid synthesis

Yield:900161-05-9 76%

Reaction Conditions:

with hydrogenchloride;water in acetone at 50 - 60; for 1 h;

Steps:

1

To a reactor equipped with an agitator, thermometer and nitrogen, were added about 10.5 kg of 2B, 68 L of acetone and 68 L of IN aqueous hydrochloric acid solution. The mixture was heated to a temperature between 50 and 60⁰C and agitated for about 1 hour before cooling to room temperature. After the reaction was judged complete, the solution was concentrated under reduced pressure to about 42 L and then cooled to a temperature between 0 and 5⁰C. The cooled mixture was agitated for an additional hour. The product 3 was filtered, washed with cooled water and dried to provide an off-white solid (6.9 kg, yield 76%). m.p. 251⁰C. Η NMR (DMSO) δ 12.8 (s, IH), 4.72 (m, J = 5.90 Hz, IH), 2.58 (m, 2H), 2.40 (m, J = 6.03 Hz, 2H), 2.21 (dd, J = 19.0, 12.8 Hz, 3H), 2.05 (m, IH), 1.87 (q, J = 8.92 Hz, IH), 1.75 (m, IH), 1.55 (m, IH), 1.35 (q, J = 12.6 Hz, IH), 1.27 (d, J = 5.88 Hz, 3H). MS (ESI) M+l m/z calcd. 267, found 267.

References:

WO2006/76564,2006,A1 Location in patent:Page/Page column 27