sodium hydroxide; 9-borabicyclo[3.3.1]nonane dimer; dihydrogen peroxide 1) THF, room temp., 1 h; Multistep reaction;

1: 1) 9-BBN, 2) aq. NaOH/30 percent H2O2 / 1) THF, room temp., 1 h 2: pyridinium-chlorochromate / CH2Cl2 / 2 h 3: 1) sodiumbis(trimethylsilyl)amide, 3) p-TSA/H2O / 1) THF, -78 deg C, 1h, 2) room temp., 12 h, 3) methanol, reflux, 3 h 4: 58 percent / pyridine View Scheme