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Multimodule Assembly Strategy for Diverted Total Synthesis and Stereochemical Determination of Laingolide A and Laingolide

submitted on 31.03.2021, 20:11 and posted on 05.04.2021, 04:28 by Chengsen Cui, Yecai Lai, Wei-Min Dai
Diverted total synthesis of diastereomers of laingolide A and laingolide has been accomplished and the stereochemistry of both (E)-enamide-containing 15-membered macrolides has been assigned. Laingolide A and laingolide have 3 and 4 stereogenic centers, respectively, and only their planar structures were reported. The former has 4 possible diastereomers while the latter has up to 8 diastereomers. A multimodule assembly (MMA) strategy was utilized to disconnect both target molecules into 5 small structural modules among which only one stereochemically varied module (stereo-module) needed to be prepared with other 4 modules available commercially. A sequence of ring-closing metathesis (RCM) and alkene isomerization was used for construction of the macrocyclic skeleton and installation of the (E)-enamide moiety. Four each diastereomers of laingolide A and laingolide have been synthesized, leading to assignment of (2R*,7R*,9S*) and (2R*,4R*,7R*,9S*) relative stereochemistry for laingolide A and laingolide, respectively. Moreover, according to the (2S,9R) absolute configuration of the congener, laingolide B, the (2S,7S,9R) and (2S,4S,7S,9R) absolute configurations are suggested for laingolide A and laingolide, respectively. The current synthetic efforts reveal, for the first time, that both laingolide A and laingolide possess the 7,9-syn-Me/t-Bu subunit.


General Research Fund grant (601211) from the Research Grant Council, The Hong Kong Special Administrative Region, P. R. China


Email Address of Submitting Author


The Hong Kong University of Science and Technology


P. R. of China

ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest