[C:1]([O:5][C@H:6]1[CH2:15][CH2:14][CH2:13][C:12]2[C@:7]1([CH3:17])[CH2:8][CH2:9][C:10](=[O:16])[CH:11]=2)([CH3:4])([CH3:3])[CH3:2].CCC(C)[BH-](C(C)CC)C(C)CC.[Li+].[OH-].[Na+].OO>O1CCCC1.O>[C:1]([O:5][C@H:6]1[CH2:15][CH2:14][CH2:13][C:12]2[C@:7]1([CH3:17])[CH2:8][CH2:9][C@H:10]([OH:16])[CH:11]=2)([CH3:4])([CH3:2])[CH3:3]A solution of 30.1 g (0.13 mole) (4aS,5S)-5-tert-butoxy-4a-methyl-4,4a, 5,6,7,8-hexahydro-2(3H)-naphtalenone in 600 ml tetrahydrofurane was cooled under stirring and Argon atmosphere to -78° C. After dropwise addition of 140 ml (0.14 mole) of L-selectride (1 molar in tetrahydrofurane),the reaction mixture was kept at -78° C. for an additional hour, then warmed to room temperature and kept at this temperature for 4.5 hours. After cooling to -15° C., 12 ml of H2O, 90 ml of 4N NaOH and 100 ml of H2O2 (30%) were added sequentially and dropwise by keeping the temperature between -10° C. to -15° C. After completed addition the reaction mixture was warmed to room temperature, poured onto water and extracted three times with ethylacetate. The combined organic layers were dried with sodium sulfate and evaporated after filtration to yield 30 g of crude (2S,4aS,5S)-5-tert-butoxy-4a-methyl-2,3,4,4a,5,6,7,8-octahydro-naphtalen-2-ol as an amorphous product shown by thin layer chromatography and NMR to be sufficiently pure for further transformations.
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