A concise synthesis of the Lycopodium alkaloid lycoposerramine Z is reported. Key to the strategy is a one-pot organocatalyzed Michael reaction followed by a domino Robinson annulation/intramolecular aza-Michael reaction promoted by LiOH, leading to enantiopure cis-decahydroquinolines.
The totalsyntheses of cyclic nitrone-containing phlegmarine-type Lycopodium alkaloids, lycoposerramines-X and -Z, were accomplished starting from (R)-3-methylcyclohexanone via Pd-catalyzed Suzuki−Miyaura coupling, Johnson−Claisen rearrangement, stereoselective hydroboration−oxidation reaction, and Mitsunobu reaction, thereby establishing the structures including the absolute configuration.
Enantioselective Total Synthesis of Lycoposerramine-Z Using Chiral Phosphoric Acid Catalyzed Intramolecular Michael Addition
作者:Lan-De Zhang、Lin-Rui Zhong、Jie Xi、Xiao-Liang Yang、Zhu-Jun Yao
DOI:10.1021/acs.joc.5b02723
日期:2016.3.4
A new enantioselective total synthesis of phlegmarine-type Lycopodium alkaloid lycoposerramine-Z (1) has been accomplished, using one-pot chemoselective sequential additions of two different Grignard reagents to the bis-Weinreb-amide intermediate and an efficient construction of the fully fuctionalized cyclohexanone intermediate with a chiral phosphoric acid catalyzed enantioselective intramolecular