反应详情

High selectivity for ketone introduction adjacent to double bonds can also be accomplished by selective bromination as shown in this example. 4-Bromoadamantylideneadamantane is prepared as follows. To a solution of 3 mmol (804 mg) of adamantylideneadamantane (X) in 40 ml of CH2Cl2 is added 6.6 mmol (1.175 g) of N-bromosuccinimide. The reaction mixture is refluxed and stirred for 12 hr. The reaction mixture is diluted with CH2Cl2 and ished twice with water and a saturated Na2S2O3 solution. The organic layer is dried over MgSO4 and evaporated. The yield of 4-bromoadamantylideneadamantane (XI) is over 95%). An analytically pure sample is obtained by crystallization from acetone and sublimation [115° C. (0.002 mm)]. Conversion of this intermediate to 4-ketoadamantilideneadamanatne (XII) is accomplished using the same procedure as in Example 4.

1. temperatureThe reaction mixture is refluxed
2. dry with materialThe organic layer is dried over MgSO4
3. customevaporated
4. customAn analytically pure sample is obtained by crystallization from acetone and sublimation [115° C. (0.002 mm)]