A convenient preparation of (1R,2S,3R,4S)-3-(neopentyloxy)isoborneol (= (1R,2S,3R,4S)-3-(2,2-dimethyl-propoxy)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol; 1a), a valuable chiral auxiliary, is described. The synthesis involves six steps starting from the readily available camphorquinone (5) and gives 1a in 48% overall yield. The key step is the chemoselective hydrolysis of the less hindered 1,3-dioxolane
方便制备(1 R,2 S,3 R,4 S)-3-(新戊氧基)异
冰片醇(=(1 R,2 S,3 R,4 S)-3-(2,2-二甲基丙氧基)-1,7,7-三甲基双环[2.2.1]庚-2-醇;1a),一种有价值的手性助剂。从容易获得的
樟脑醌(5)开始,合成过程涉及六个步骤,总产率为48%的1a。关键步骤是
樟脑醌二
缩醛4中受阻较少的
1,3-二氧戊环部分的
化学选择性
水解。