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Abstract

Treatment of iodolactone 8a, having a cyclopentano[c]pyran skeleton and deriving from aucubin (1) (Scheme 1), with sodium trimethylsilanolate permitted a straightforward rearrangement to bicyclo[3.1.0]hexenes 10a and 10b (Schemes 3 and 4). Introduction of an N-atom via a modified Curtius reaction provided an easy entry to fused aminocyclopentitols (Schemes 4 and 5). Target 4 is a conformationally restricted cyclopropanefused analogue of the glycosidase inhibitors mannostatins A (2) and B (3).

Influence of solvents and catalysts on the formation and hydrolysis of polyfunctional enoxysilanes derived from aucubin

“…Different works done until now on the semisynthesis from aucubin led to develop contraction of pyran ring to furan or cyclopropane 14 or homologation in C-4.…”

“…Grimshaw in 1960, 4 this naturally occurring material devoid of cytotoxic activity, [5][6][7] is used for several decades by organic chemists for the synthesis of chiral building blocks or scaffolds. [8][9][10][11][12][13][14][15][16] Aucubin permitted the synthesis of various classes of biologically interesting chiral compounds: insect antifeedants, 17 carbocyclic nucleoside analogues, cytotoxic cyclopentenone glucosides, [21][22] chiral rigid -amino acid glucosides 23 and polyaminoiridoids whose have similar polarity with aminoside antibiotics. 24 For those syntheses, functional or skeletal modifications were applied to aucubin and sometimes with an innovative chemistry.…”

A novel series of cytotoxic iridoid glucosides derived from aucubin: Design, synthesis and structure–activity relationships

“…Aucubin (1), linaride (8), 6,10-deoxyaucubin (9), and 6-Oacetyllinaride (10) were treated with pivaloyl chloride to give perpivaloylaucubin (12) [6], perpivaloyllinaride (13), 6,10-O-deoxy-2 0 ,3 0 ,4 0 ,6 0 -tetra-O-pivaloylaucubin (14), and 6-O-acetyl-2 0 ,3 0 ,4 0 ,6 0 -tetra-O-pivaloyllinaride (15), respectively, in 70e80% yields. Selective deprotection of the acetyl group of 15 to afford 16 was ensured by the use of potassium cyanide [26].…”

“…Finally, the access to the desired unsaturated iridolactones 3e7, was envisioned through a regioselective two or three-steps procedure previously developed in our group [6]. The selective oxidation of the dihydropyran 3,4-double bond of intermediates 12e14 with N-iodosuccinimide in aqueous MeCN gave the corresponding iodolactols, as diastereoisomeric mixtures.…”

“…It was first used in 1979 as natural chiral precursor in the synthesis of various prostaglandins [3]. Subsequently, several research groups modified its structure to prepare insect antifeedants [4], carbocyclic nucleoside analogues [5], aminocyclopentitol glycosidase inhibitors [6], and aminoside antibiotics analogues [7].…”