Resolution of an iridoid synthon, gastrolactol, by means of dynamic acetylation and lipase-catalyzed alcoholysis.
A short synthetic route to asymmetric iridoids was developed. The three key steps were an intramolecular [4 + 2] cycloaddition reaction of an enamine derivative of 8-oxocitral (2), a dynamic acetylation, and an enzymatic resolution of the gastrolactyl acetates 5a and 5b, iridoids with three stereocenters. Some regio- and stereoselective heterogeneous catalytic hydrogenations of double bonds in iridoid aglucones were discussed.
Santangelo
E M
EM
Department of Organic Chemistry, Royal Institute of Technology, SE -100 44 Stockholm, Sweden.
Rotticci
D
D
Liblikas
I
I
Norin
T
T
Unelius
C R
CR
D000107:Acetylation; D002384:Catalysis; D008049:Lipase / Q000378:metabolism*; D008968:Molecular Conformation; D013729:Terpenes / Q000138:chemical synthesis* / Q000737:chemistry
D013729:Terpenes; C434291:gastrolactol; D008049:Lipase