Methyl pseudomonate

Stereoselective epoxidation of an allylic alcohol (5. 75-76 9, 81-82). The antibiotic methyl pscudomonatc A (2) is the -epoxide of methyl pseudomonate C. Epoxidation of methyl pseudomonate C with m-chloropcrbenzoic acid in CH.Cl. 

The produced biologically active material upon methylation with diazomethane in ether showed two spots by thin layer chromatography corresponding to methyl pseudomonate as the major component and a minor amount of component methyl pseudomonate-A (ratio ca 9 1 by wt.). 

Methyl pseudomonate was separated from methyl pseudomonate-A by preparative layer silica gel (GF245) chromatography on development with chloroform/isopropanol (9 1). 50% of methyl pseudomonate was recovered from the impure residue by crystallization from benzene/petroleum ether to give colorless needles of m.p. 76.5-78°C. 

Methylphenylpropylphosphine, 387 Methyl phenyl selenoxide, 291 (2-Methyl-2-propenyl)trimethylsilane, 7 Methyl pseudomonate A, 66 Methyl pseudomonate C, 66 N-Methylpyrrolidone, 176 Methyl salicylates, 257 a-Methylseleno ketones, 345 1-Methylseleno-l-lithiocyclopropane, 318 3-Methyl-2-selenoxo-l,3-benzothiazole, 270... 

In a synthesis of (+)-methyl pseudomonate (21), D-xylose provided the tetrahydropyran fragment (22) via a C-cyano glycoside derivative, and the chiral sidechain was elaborated from D-glucose as indicated in Scheme 5. ° ri another enantiospecific synthesis of pseudomonic acids, D- and L-arabinose were used to prepare the two fragments (23) and (24) respectively, which were then condensed in... 

Marko et al. employed an enantioselective Noyori BINAL-H reduction in the synthesis of methyl monate C (11), the methyl ester derivative of the potent antibiotic pseudomonic acid C6 (Scheme 4.3e). The a,(3-unsaturated ketone 12 underwent the Noyori reduction with the (S)-BINAL-H reagent to give the product desired (13) in 70% yield and 95% ee. The chiral alcohol was then condensed... 

Fleet, G W J, Shing, T K M, Enantiospecific synthesis of (35 -hydroxy-25 -methyl) butyl triphenylphosphonium iodide a precursor for the chiral side chain of pseudomonic acid. Tetrahedron Lett., 24, 3657-3660, 1983. 

Pseudomonic acid A can be hydrolysed to monic acid A, which can then be converted into a variety of semi-synthetic esters and amides, many of which are herbicidal because they inhibit ITRS in plants. As noted above, this was the first time that herbicidal inhibitors of this enzyme had been discovered, so this important observation validated a new mode of action for herbicides. Even the simple methyl ester of monic acid A has some... 

Synthesis of (-l-)-Pseudomonic Acid C. A total synthesis of (-l-)-pseudo-monic acid C employes an n-lkoSnH-mediated reductive elimination of the methyl xanthate derivative of a (5-hydroxy sulfone as one of the key steps (Eq. 160)."... 

Synonyms [2S-[2a(E),3p,4(3,5a[2R, 3R (lR, 2R )]]]-9-3-Methyl-l-oxo-4-[tetrahydro-3,4-dihydroxy-5-[[3-(2-hydroxy-l-methylpropyl)oxiranyl]methyl]-2H-pyran-2-yl]-2-butenyl]oxy]nonanoic acid pseudomonic acid A, trans-pseudomonic acid... 

---