Asymmetric total synthesis of caribenol A via an intramolecular diels-alder reaction
A total synthesis of the caribenol A (1), a novel natural product with an intriguing tetracyclic framework, has been achieved. The synthesis features an intramolecular Diels-Alder (IMDA) reaction for the facile construction of the tricyclic [5-7-6] skelet
A short formal total synthesis of (±)-hirsutic acid
A short formal total synthesis of (±)-hirsutic acid is described using a Claisen rearrangement and a radical cascade as the key steps. The radical sequence involves an intermolecular addition of a radical derived from a xanthate followed by a cyclization and transfer of the xanthate group.
Revol, Guillaume,Fuchs, Christian,Zard, Samir Z.
p. 927 - 931
(2013/02/22)
Stereoselective synthesis of 4'-α-alkylcarbovir derivatives based on an asymmetric synthesis or chemoenzymatic procedure
Stereoselective synthesis of 4'-α-alkylcarbovir derivatives 4 was described based on asymmetric synthesis or a chemoenzymatic procedure. The asymmetric alkylation of chiral acetal 7 gave the alkylated enol ethers 9a - c possessing a chiral quaternary carbon. The key carbocyclic intermediates 14a - c were synthesized from 9a - c via eleven-steps. Coupling of 14a - c with 2-amino-6-chloropurine followed by desilylation and subsequent hydrolysis afforded the target compounds 4a - c in moderate yield. The optically active cyclopentene intermediates 5a - c and 6a - c were also prepared by enzymatic resolution of (±)-5a - c and (±)-6a - c, respectively.