Application of Electrocyclic Ring-Opening and Desymmetrizing Nucleophilic Trappings of <i>meso</i>-6,6-Dibromobicyclo[3.1.0]hexanes to Total Syntheses of Crinine and Haemanthamine Alkaloids
作者:Ping Lan、Martin G. Banwell、Anthony C. Willis
DOI:10.1021/acs.joc.9b00018
日期:2019.3.15
radical cyclization, and Pictet–Spengler reactions, into (−)- or (+)-crinane (1 or ent-1, respectively). Variations on these protocols were applied to the total syntheses of (+)- and (−)-11-hydroxyvattitine [(+)- and (−)-3], (+)- and (−)-bulbispermine [(+)- and (−)-4], (+)- and (−)-haemanthamine [(+)- and (−)-5], (+)- and (−)-pretazettine [(+)- and (−)-6], and (+)- and (−)-tazettine [(+)- and (−)-7] as
在手性,非外消旋1°-胺28存在下,C 2对称(内消旋)6,6-二溴双环[3.1.0]己烷(如10)的热诱导开环得到约1 。非对映异构体和色谱上可分离的1-氨基-2-溴-2-环己烯的1:1混合物37(42%)和38(45%)。每个步骤都经过了13个步骤的详细阐述,包括Suzuki-Miyaura交叉偶联,自由基环化和Pictet-Spengler反应,转变为(-)-或(+)-三氢呋喃(1或ent - 1, 分别)。这些协议的变化适用于(+)-和(-)-11-羟基vattitine [(+)-和(-)- 3 ],(+)-和(-)-bulbispermine [(+) -和(-)- 4 ],(+)-和(-)-甘露胺[[+]-和(-)- 5 ],(+)-和(-)-Pretazettine [[+]-和(- )-6 ],以及(+)-和(-)-他zetine [[+]-和(-)- 7 ]以及(±)-hamayne