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In an extension of our studies on low-temperature rearrangements of 1-alkynyl ethers, we describe herein the [3,3]-sigmatropic rearrangement of in situ formed propargyl alkynyl ethers to allenyl ketenes, which furnish complex tert -butyl-(2 E ,4 Z )-dienoates 2 in good yields upon tert -butanol addition. Similarly, sigmatropic rearrangements of in situ formed propargyl lithioalkynyl ethers yield methyl-(2 Z ,4 Z )-dienoates 4 upon methanol addition or unsaturated lactones 6 upon aldehyde or ketone addition to the allenyl ynolate intermediate.
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This content will become publicly available on March 14, 2026
Synthesis of Leiodolide A Macrolactone
ABSTRACT: A convergent route toward the synthesis of leiodolide A (1) is described. Our studies explore reactions of the indium chloride-induced transmetallation of allylic stannane 32 for nucleophilic addition with nonracemic aldehyde 15. The stereoselective formation of the all-syn stereotriad was rationalized by in situ isomerization to produce the Z-allylindium reagent for subsequent anti-Felkin addition. The inversion of C17 stereochemistry led to an effective -allyl Stille cross cou-pling utilizing Z-alkenylstannane 11b. The Horner–Wadsworth–Emmons reaction provides macrolactone 37 which exhibits discrepancies as compared to reported NMR data for purported leiodolide A.
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- Award ID(s):
- 2102587
- PAR ID:
- 10637320
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Organic Letters
- Volume:
- 27
- Issue:
- 10
- ISSN:
- 1523-7060
- Page Range / eLocation ID:
- 2284 to 2288
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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