Synlett 2022; 33(14): 1377-1382
DOI: 10.1055/a-1806-6089
cluster
Organic Chemistry in Thailand

Diastereoselective Synthesis of Tetrahydrofurano[2,3-g]indolizidines and 8-Aminoindolizidines from l-Asparagine

Punlop Kuntiyong
,
Nantachai Inprung
,
Sineenart Attanonchai
,
Wichita Kheakwanwong
,
Pijitra Bunrod
,
Sunisa Akkarasamiyo
The funding for this work was provided by the Thailand Research Fund (TRF) grants RSA6180040, DBG6080007, and The National Research Council of Thailand (NRCT) grant 2562#11892.


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Abstract

8-Aminoindolizidines were synthesized from l-asparagine as the chiral starting material. The key dibenzylamino succinimide intermediate was synthesized in two steps. Three homologs of chiral hydroxy lactams tethered with hydroxyalkenes were synthesized from the succinimide through a sequence involving N-alkylation, cross-olefin metathesis, and hydride reduction. The dibenzylamino group gave stereocontrol of the key N-acyliminium ion cyclization of these hydroxy lactams. 5-Substituted aminoindolizidines were synthesized with high diastereoselectivity at C6. A tandem cyclization of an N-(6-hydroxyhex-3-en-1-yl) γ-hydroxy lactam resulted in the formation of a tetrahydrofurano[2,3-g]indolizidine system.

Supporting Information



Publication History

Received: 14 February 2022

Accepted after revision: 23 March 2022

Accepted Manuscript online:
23 March 2022

Article published online:
25 April 2022

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