Formal total synthesis of (–)- and (+)-balanol: two complementary enantiodivergent routes from vinyloxiranes and vinylaziridines
作者:Jacqueline Gilmet、Bradford Sullivan、Tomas Hudlicky
DOI:10.1016/j.tet.2008.10.070
日期:2009.1
Formal total syntheses of both enantiomers of balanol have been achieved by the preparation of the protected hexahydroazepine core 2. Two complementary routes have been investigated. The first relied on the regioselective opening of 1,2-epoxycyclohex-3-ene with a chiral-auxiliary version of the Burgess reagent to provide a diastereomeric pair of cis-fused cyclic sulfamidates. The sulfamidates were
通过制备受保护的六氢氮杂core核2,已实现了Balanol的两种对映异构体的正式全部合成。已经研究了两种互补的途径。第一个依靠手性辅助形式的Burgess试剂对1,2-环氧环己-3-烯的区域选择性开放,以提供非对映异构体对的顺式稠合环状氨基磺酸酯。用苯甲酸铵将氨基磺酸盐转化为反式氨基苯甲酸酯,并且在分离后,通过氧化裂解和还原胺化将其转化为(-)- 2和(+)- 2。第二种方法是使用由1-溴-2,3-二羟基环己-4,6-二烯衍生的乙烯基氮丙啶,后者是通过对溴苯进行全细胞发酵而获得的。大肠杆菌JM109(pDTG601)。氮丙啶的立体选择性开放产生了必需的反式-氨基醇衍生物,其在乙烯基溴部分饱和后通过顺式-二醇的氧化裂解和还原性胺化而转化为(-)- 2和(+)- 2。提供了所有新化合物的实验数据和光谱数据。