Enantioselective reaction of α-thio carbanion derived from 1-phenyl-1-(phenylthio)-1-(tributylstannyl)methane with cis-bicyclo[3.3.0]octane-3,7-dione monoethylene ketals in the presence of bis(oxazoline)s gave products with high diastereoselectivity and with high enantioselectivity. The reaction of α-seleno carbanions derived from bis(phenylseleno)arylmethanes also showed high diastereoselectivity and enantioselectivity. Deprotection and subsequent stereospecific elimination afforded axially chiral cis-arylmethylenebicyclo[3.3.0]octanes with high enantioselectivity (up to 99% ee).
由 1-苯基-1-(苯
硫基)-1-(三
丁基锡烷基)
甲烷衍生的 α-
硫代碳酰基与顺式-
双环[3.3.0]辛烷-3,7-二酮单
乙烯酮在双(
噁唑啉)s 的存在下进行的对映体选择性反应得到了具有高非对映选择性和高对映体选择性的产物。由双(苯基
硒)芳基
甲烷衍生出的α-
硒碳离子的反应也显示出高非对映选择性和高对映选择性。通过去保护和随后的立体特异性消除,可以得到轴向手性的顺式芳基亚甲基双环[3.3.0]
辛烷,对映体选择性高(ee高达 99%)。