49686-57-9Relevant articles and documents
Collective Asymmetric Total Synthesis of C-11 Oxygenated Cephalotaxus Alkaloids
Kim, Jae Hyun,Jeon, Hongjun,Park, Choyi,Park, Soojun,Kim, Sanghee
, p. 12060 - 12065 (2021/04/29)
While numerous studies pertaining to the total synthesis of Cephalotaxus alkaloids have been reported, only two strategies have been reported to date for the successful synthesis of the C-11 oxygenated subset, due to the additional synthetic challenge posed by the remote C-11 stereocenter. Herein, we report the collective asymmetric total synthesis of C-11 oxygenated Cephalotaxus alkaloids using a chiral proline both as a starting material and as the only chirality source. A tetracyclic advanced intermediate was synthesized in a highly stereoselective manner from l-proline in 8 steps involving sequential chirality transfer steps such as a diastereoselective N-alkylation, stereospecific Stevens rearrangement and intramolecular Friedel–Crafts reaction via an unusual O-acyloxocarbenium intermediate. From a common intermediate, the asymmetric total synthesis of six C-11 oxygenated Cephalotaxus alkaloids was completed by a series of oxidation state adjustments.
Total synthesis of the Cephalotaxus alkaloids dl-cephalotaxine, dl-11-hydroxycephalotaxine, and dl-drupacine
Burkholder,Fuchs
, p. 9601 - 9613 (2007/10/02)
This paper reports the chemical details of our total synthesis of dl-cephalotaxine (1) and the completion of the first total synthesis of dl-11-hydroxycephalotaxine (3) and dl-drupacine (4). Key steps in the synthesis of dl-cephalotaxine include: (1) conj
