Synthesis and Circular Dichroism of Optically Pure (±)-(1<i>S</i>,2<i>S</i>,5<i>S</i>)-5-Methoxy-3,4,6,7-tetramethylidenebicyclo[3.2.1]oct-2-yl Derivatives. Baker's Yeast Reduction of 4-Methoxy-5,6,7,8-tetramethylidenebicyclo[2.2.2]octan-2-one
作者:Gérald Burnier、Pierre Vogel
DOI:10.1002/hlca.19900730425
日期:1990.6.20
Baker's yeast reduction of 4-methoxy-5,6,7,8-tetramethylidenebicyclo[2.2.2]octan-2-one (11) under fermenting conditions afforded (−)-(1S,2S,4R)-4-methoxy-5,6,7,8-tetramethylidenebicyclo[2.2.2]octan-2-ol ((−)-13) in 60% yield with an e.e. > 99.5%. Its methanesulfonate (−)-14 was hydrolyzed and rearranged with high stereo-selectivity into (+)-(1S,2S,5S)-5-methoxy-3,4,6,7-tetramethylidenebicyclo[3.2.1]octan-2-ol
在发酵条件下贝克酵母还原4-甲氧基-5,6,7,8-四亚甲基双环[2.2.2] octan-2-one(11)得到(-)-(1 S,2 S,4 R)-4 -甲氧基-5,6,7,8-四亚甲基双环[2.2.2]辛烷-2-醇((-)- 13)的产率为60%,ee≥99.5%。将其甲磺酸盐(-)- 14水解并以高立体选择性重排为(+)-(1 S,2 S,5 S)-5-甲氧基-3,4,6,7-四亚甲基双环[3.2.1]辛烷-2-醇((+)- 15)。(-)- 13的绝对构型由其4-(二甲基氨基)苯甲酸酯((+)- 22)应用手性激子偶联方法。(+)- 15及其(叔丁基)二甲基甲硅烷基醚((+)- 23)的CD光谱显示,激子分裂类型的Cotton效应归因于s - gauche -buta-diene与仲顺丁二烯这些系统的发色团。