The solvolysis reaction of (4,5)-anti-4-aryl-5-tosyloxy-2(E)-hexenoates 4a-k gave (4,5)-anti-4-aryl-5-hydroxy-2(E)-hexenoates 2a-k and (4,5)-anti-5-aryl-4-hydroxy-2(E)-hexenoates 5a-k along with the complete inversion. This 1,2-aryl migration was induced by treatment with heating in water-saturated nitromethane. On the basis of the substituent effect on the aromatic ring, this 1,2-aryl migration is
Total Synthesis of (S)-(+)- and (R)-(-)-Curcudiols Based on 1,2-Aryl Migration via Phenonium Ion
作者:Hiroyuki Akita、Takeru Ehara、Hirofumi Yokoyama、Machiko Ono
DOI:10.3987/com-06-10972
日期:——
Total synthesis of (S)-(+)- and (R)-(-)-curcudiols (2) was achieved based on the 1,2-arylmigration of the (4R,5R)- and (4S,5S)-4-aryl-5-tosyloxy-(2E)-hexenoates (9) derived from (4R,5R)- and (4S,5S)-4-epoxy-(2E)-hexenoates (3), respectively.
Lactonization of methyl 4-aryl-5-tosyloxy hexanoate 3 via a phenonium ion gave γ-lactone 4 selectively under thermodynamical conditions while it afforded δ-lactone 5 preferentially under kinetic conditions.