Synthesis of 2-Substituted (±)-(2<i>R,</i>3<i>R,</i>5<i>R</i>)-Tetrahydrofuran-3,5-dicarboxylic Acid Derivatives
作者:Gary T. Wang、Sheldon Wang、Yuanwei Chen、Robert Gentles、Thomas Sowin
DOI:10.1021/jo001551a
日期:2001.3.1
of 2-substituted (+/-)-(2R,3R,5R)-tetrahydrofuran-3,5-dicarboxylic acid derivatives has been developed. Starting from 5-norborne-2-ol, the key intermediate (+/-)-methyl 5,6-exo,exo-(isopropylidenedioxy)-2-oxabicyclo[2.2.1]heptane-3-exo-carboxylate (15) was synthesized in an efficient six-step sequence. The key transformation is the base-catalyzed methanolysis-rearrangement of (+/-)-6,7-exo,exo-(isop
已经开发了2-取代的(+/-)-(2R,3R,5R)-四氢呋喃-3,5-二羧酸衍生物的有效合成。从5-降冰片-2-醇开始,关键中间体(+/-)-甲基5,6-exo,exo-(异丙基二烯二氧基)-2-氧杂双环[2.2.1]庚烷-3-exo-羧酸盐(15)以有效的六步顺序合成了。关键的转化是(+/-)-6,7-exo,exo-(isopropylidenedioxy)-4-exo-iodo-2-oxabicyclo [3.2.1] octan-3-one()的碱催化甲醇重排14)。进一步操纵(+/-)-甲基5,6-甲基,exo-(异丙基二烯二氧基)-2-氧杂双环[2.2.1]庚烷-3-exo-羧酸盐(15)的3-取代基,然后将其脱保护RuCl(3)/ NaIO(4)催化的二醇部分和开环反应以高收率得到标题化合物。