Stereocontrolled syntheses of (−)- and (+)-γ-diisoeugenol along with optically active eight stereoisomers of 7,8′-epoxy-8,7′-neolignan
作者:Tatsuaki Takubo、Nao Kikuchi、Hisashi Nishiwaki、Satoshi Yamauchi
DOI:10.1039/d1ob00008j
日期:——
Friedel–Crafts reaction gave exclusively indane with (7S,7′S,8R,8′R)-2,7′-cyclo-7,8′-neolignan structure 18 along with (7S,7′R,8S,8′R)-7,8′-epoxy-8,7′-neolignan structure 19. Indane 18 was converted to (−)-γ-diisoeugenol ((−)-4). On the other hand, (2S,3R,4R,5S)-3,5-bis(4-benzyloxy-3-methoxyphenyl)-2,4-dimethyltetrahydro-3-furanol 22 did not afford indane, but the tetrahydrofuran structure with (7S,7′S,8S,8′S)-7
结果表明,(2 R,3 S,4 R,5 S)-3,5-双(4-苄氧基-3-甲氧基苯基)-2,4-二甲基四氢-3-呋喃醇的叔苄基羟基还原17,随后分子内Friedel-Crafts反应,得到二氢化茚只与(7小号,7'小号,8 - [R,8' - [R)-2,7'-环7,8'-新木脂素结构18具有沿(7小号, 7' - [R,8小号,8' - [R)-7,8'环氧8,7'-新木脂素结构19。茚满18转化为(-)-γ-二异丁香酚((-)- 4)。另一方面,(2 S,3 R,4 R,5 S)-3,5-双(4-苄氧基-3-甲氧基苯基)-2,4-二甲基四氢-3-呋喃醇22没有提供茚满,但具有(7 S,7 'S,8 S,8 'S)-7,8'-环氧-8,7'-neolignan结构23和7'- epi - 23的四氢呋喃结构。