Stereoselective total synthesis of Jaspine B (Pachastrissamine) utilizing iodocyclization and an investigation of its cytotoxic activity

The stereoselective synthesis of Jaspine B has been achieved from easily available (S)-Garner’s aldehyde. The trisubstituted tetrahydrofuran core of Jaspine B was constructed by utilizing a diastereoselective iodocyclization as the key step. Deiodination and debenzylation were performed in a single step by using n-Bu3SnH and ABCN as a conjugate catalyst system. The in vitro cytotoxicity of compounds 1 and 1a against 3 human cancer cell lines-A549 (lung), MCF7 (breast), and KB (oral); and a non-cancer cell line (NIH3T3) was determined by sulphorhodamine B based assay.

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(2S,3S,4S)-4-Amino-2-tetradecyltetrahydrofuran-3-olC18H37NO2[α]D17=+8.6 (c 0.32, CH3OH)Source of chirality: (S)-Garner’s aldehydeAbsolute configuration: (2S,3S,4S)

(S)-tert-Butyl 4-((R)-1-hydroxyallyl)-2,2-dimethyloxazolidine-3-carboxylateC13H23NO4[α]D29=-34.2 (c1.21 CH3OH)Source of chirality: (S)-Garner’s aldehydeAbsolute configuration: (3S,4R)

(S)-tert-Butyl 4-((R)-1-(benzyloxy)allyl)-2,2-dimethyloxazolidine-3-carboxylateC20H29NO4[α]D29=-47.9 (c0.42 CHCl3)Source of chirality: (S)-Garner’s aldehydeAbsolute configuration: (3S,4R)

tert-Butyl (3S,4S,5R)-4-(benzyloxy)-5-((S)-1-iodotetradecyl)tetrahydrofuran-3-ylcarbamateC30H50INO4[α]D28=-1.9 (c 0.34, CHCl3)Source of chirality: (S)-Garner’s aldehydeAbsolute configuration: (3S,4S,5R,6S)

tert-Butyl (3S,4S,5S)-4-(benzyloxy)-5-tetradecyltetrahydrofuran-3-ylcarbamateC30H51NO4[α]D28=-8.0 (c 0.16, CHCl3)Source of chirality: (S)-Garner’s aldehydeAbsolute configuration: (3S,4S,5S)

tert-Butyl (3S,4S,5S)-4-hydroxy-5-tetradecyltetrahydrofuran-3-ylcarbamateC23H45NO4[α]D26=+7.8 (c 0.24, CHCl3)Source of chirality: (S)- Garner’s aldehydeAbsolute configuration: (3S,4S,5S)