4942-47-6

17768-36-4

General procedure for the synthesis of 3-hydroxy-1-adamantaneacetic acid from 1-adamantaneacetic acid: adamantanecarboxylic acid (1a-1s, 3.5 g) was added in batches to a mixture comprising 2.5-3 or 7 equivalents of MnO2 and 2.5-14 mL of 93% H2SO4, pre-cooled to -30 °C, with the reaction maintained at a temperature of less than 25 °C, under vigorous stirring. The reaction mixture was maintained at this temperature for 0.5-24 hours and subsequently treated with cold water under ice bath cooling. The precipitate was collected by filtration and washed with a small amount of water and butan-1-ol. The product was extracted with butan-1-ol (5 x 2 mL). For the isolation of the products 2j-21 and 2q-2s, it was necessary to adjust the mixture to pH 3-4 with 30% aqueous sodium hydroxide solution prior to extraction. all organic phases were combined, washed sequentially with water, sodium bicarbonate solution, and water, and then dried by azeotropic distillation. Finally, the solvent was removed under reduced pressure on a rotary evaporator and the target product 3-hydroxy-1-adamantaneacetic acid was purified by recrystallization.