Lipase-catalyzed asymmetric synthesis of naphtho[2,3-c]furan-1(3H)-one derivatives by a one-pot dynamic kinetic resolution/intramolecular Diels–Alder reaction: Total synthesis of (−)-himbacine

The role of biocatalysis in the asymmetric synthesis of alkaloids – an update

“…In the second case, DKR using Novozym 435 and the oxovanadium catalyst transformed the open-chain allylic alcohol 44 into the ester ( R )-46, which upon heating to reflux underwent an intramolecular Diels–Alder cycloaddition that afforded the lactone 47 in 98% ee and as a 4 : 1 mixture of diastereomers ( Scheme 7c ). 52 Treatment with DBU in dichloromethane at room temperature quantitatively converted this isomeric mixture into diene 48, and this intermediate was further elaborated into (−)-himbacine in 16 steps.…”

Progress on the Stereoselective Synthesis of Chiral Molecules Based on Metal-Catalyzed Dynamic Kinetic Resolution of Alcohols with Lipases

“…Akai and coworkers have recently developed the one-pot synthesis of optically active naphtho[2,3-c]furan-1(3H)-one derivatives used in the total synthesis of the alkaloid (-)himbacine [62,63]. The tricyclic compounds were obtained as a 4/1 diastereomeric mixture (98% ee for each diastereomer) starting from dienols and an acrylic ester as an acylating agent (Scheme 19).…”

The Impact of Recent Developments in Technologies which Enable the Increased Use of Biocatalysts

“…The oxovanadium catalyst carried out a racemization/isomerization of the allylic alcohol starting material. As an illustrative example, this methodology was applied to the total synthesis of (–)‐himbacine (–)‐ 38 , furnishing the product with excellent enantioselectivity …”