Studies directed toward the total synthesis of the ezomycins, the octosyl acids and related antibiotics

Prognostic factors for survival in patients with compensated cirrhosis and small hepatocellular carcinoma after percutaneous ethanol injection therapy

“…As a result, it was found that the N ‐cytidinyl analogue 63 was at least as active as malayamycin A itself 48f. The stereocontrolled synthesis of 1,2‐ trans ‐ N ‐nucleosides from thioglycosides46b, 48c,f was a key step in the synthesis of various pyrimidine and purine analogues of N ‐malayamycin. Interestingly, fungicidal activity was highly dependent on the nature and stereochemistry of substituents as well as the heterocyclic anomeric unit.…”

Synthesis of β-C-galactosyl d- and l-alanines

“…The trans -fused bicyclic compounds 9 and 10 could serve as valuable intermediates in the synthesis of the Ezomycin group of antibiotics and related analogs. 38 …”

“…The trans-fused bicyclic compounds 9 and 10 could serve as valuable intermediates in the synthesis of the Ezomycin group of antibiotics and related analogs. 38 Although quite interesting, the cyclization was an obvious obstacle in the planned synthesis of C-glycosyl amino acids. After some experimentation, it was realized that, the adventitious cyclization could be circumvented by using tosylates or mesylates in place of triflates (Scheme 5).…”

Total synthesis of the ionophore antibiotic X-14547A (Indanomycin)

“…Synthesis of the Left-Hand Enal (3). Nicolaou12b reported that the unsaturated aldehyde 3 could be obtained from the natural product, albeit in low yield, by osmium-catalyzed periodate cleavage of indanomycin methyl ester (35). In our hands high yields of this com- pound, suitable for coupling studies with the right-hand sulfone 5 could best be obtained by careful ozonolysis of 35 at -78 °C.…”

“…The SEM protecting group was removed cleanly in 72% yield by treatment with a dry, concentrated solution of tetra-n-butylammonium fluoride in THF.47,48 The product was identical to indanomycin methyl ester 35 prepared from the natural product by esterification using diazomethane.…”