Beilstein J. Org. Chem.2018,14, 547–552, doi:10.3762/bjoc.14.41
An electrochemical version of the Corey–Winterreaction was developed giving excellent results in aqueous methanol media (MeOH/H2O (80:20) with AcOH/AcONa buffer 0.5 M as supporting electrolyte), using a reticulated vitreous carbon as cathode in a divided cell. The electrochemical version is much
-(pent-1-enyl)-α-pyrone and trans-6-(pent-1,4-dienyl)-α-pyrone, which are naturally occurring metabolites isolated from Trichoderma viride and Penicillium, in high chemical yield and with excellent stereo selectivity.
Keywords: Corey–Winterreaction; electrosynthesis; 6-pentyl-2H-pyran-2-ones; reduction
; thiocarbonates; Findings
The Corey–Winterreaction (also known as the Corey–Winter reductive olefination) is a chemical transformation that permits the conversion of 1,2-diols A into E-alkenes C via the formation and reduction of a cyclic thiocarbonate intermediate B (Scheme 1) [1][2]. In general this reaction
Beilstein J. Org. Chem.2017,13, 2326–2331, doi:10.3762/bjoc.13.229
,3α-, and 2β,3β-dihydroxy-, 3-keto-, 3α- and 3β-hydroxy-, 2α-hydroxy-3-keto-) were synthesized from 2α,3α-diols in a few simple steps (Corey–Winterreaction, epoxidation, oxidation, hydride reduction, etc.).
Keywords: biosynthetic precursors; brassinosteroids; diols; epibrassinolide; epicastasterone
epibrassinolide (2) into the corresponding Δ2-steroids. The first route comprised the selective protection of the side chain diol in 1 and 2 through exhaustive acetylation followed by saponification of the intermediate tetraacetates under controlled conditions [14]. Next, a Corey–Winterreaction [15] of the
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Graphical Abstract
Scheme 1:
Structural features of epicastasterone (1), epibrassinolide (2) and A-ring units 3–12 of BS biosynt...