nor-Mevaldic acid surrogates as selective antifungal agent leads against Botrytis cinerea. Enantioselective preparation of 4-hydroxy-6-(1-phenylethoxy)tetrahydro-2H-pyran-2-one

Abstract

Solvent-free desymmetrisation of meso-dialdehyde 1 with chiral 1-phenylethan-1-ol, led to preparation of 4-silyloxy-6-alkyloxytetrahydro-2H-pyran-2-one (+)-3a with a 96:4 dr Deprotected lactone (+)-19a and the related racemic lactones 16a-18a present a lactone moiety resembling the natural substrate of HMG-CoA reductase and their antifungal properties have been evaluated against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. These compounds were selectively active against B. cinerea, while inactive against C. gloeosporioides.

General Synthesis of meso-1,4-Dialdehydes and Their Application in Ir-Catalyzed Asymmetric Tishchenko Reactions

“…In 1,5-dialdehydes, where the distance between the two formyl groups is shorter, cyclic hydrates are formed . In some cases; such cyclic hydrates can be converted to the corresponding dialdehydes by refluxing in tetrahydrofuran (THF) in the presence of 4A molecular sieves. , To avoid hydrate formation in the synthesis of 1,5-dialdehydes, Rein’s method based on Swern oxidation followed by workup under nonaqueous conditions is often used …”

“…In the last four decades, 1,5-prochiral, − 1,5- meso -, − 1,6-prochiral, − 1,6- meso -, − and 1,7- meso -dialdehydes ,,,− , have been synthesized (Figure ) using various methods, including the Swern oxidation of the corresponding diols, − ,,, pyridinium-chlorochromate oxidation, tetrapropylammonium-perruthenate oxidation, oxidative cleavage of diols using H 5 IO 6 ,,,, or NaIO 4 , and ozonolysis of alkenes. ,,, The purification of 1,7- meso -dialdehydes by column chromatography on silica gel has also been reported, albeit that these dialdehydes are generally used without purification. In 1,5-dialdehydes, where the distance between the two formyl groups is shorter, cyclic hydrates are formed .…”

“…10 In some cases; such cyclic hydrates can be converted to the corresponding dialdehydes by refluxing in tetrahydrofuran (THF) in the presence of 4A molecular sieves. 6,9 To avoid hydrate formation in the synthesis of 1,5dialdehydes, Rein's method based on Swern oxidation followed by workup under nonaqueous conditions is often used. 11 Special 1,4-prochiral dialdehydes such as 1,2-diformylferrocene 34−36 can be prepared via oxidation of a dimethylamino group with MnO 2 34,35 or hydrolysis of acetal, 36 and these are sufficiently stable to withstand purification by column chromatography on silica gel.…”

Design, Synthesis, Bioactive Evaluation, and Molecular Dynamics Simulation of Novel 4H-Pyrano[3,2-c]pyridine Analogues as Potential Sterol 14α-Demethylase (CYP51) Inhibitors

“…Pyran backbones have become one of quite important bioactive fragments. New compounds with pyran backbones as potential fungicides are constantly discovered. − …”

Molecular Targets of Herbicides and Fungicides─Are There Useful Overlaps for Fungicide Discovery?

“…Moreover, there are strong inhibitors that could be the basis for either fungicide or herbicide development of these common molecular targets. For example, inhibitors of hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) (often termed statins) are both highly phytotoxic and antifungal. − HMG-CoA reductase as a herbicide and insecticide target is discussed in detail are in a recent paper . However, this review will deal with only commercial herbicide molecular targets that might also become targets for fungicides.…”