Total synthesis of boromycin

Enantioselective Synthesis of cis-3-Oxy-2,2,6,6-tetrasubstituted Tetrahydropyrans

“…Having established the stereochemistry of compound 12 at C-2, we proceeded to do the same with the other three remaining tetrahydropyrans. Reduction with HSnBu 3 24 of the four tetrahydropyrans gave two diols (16 and 20) as expected. The structure of alcohol 16 has been established previously and, as the only difference between 16 and 20 is the stereochemistry of C-2, the structure for 20 is shown in Scheme 5, and so the stereochemistry for all the tetrahydropyrans at C-2 is determined.…”

Enantiodivergent Transannular Rearrangement of 3‐Isopropyl‐1,4‐benzodiazepine‐2,5‐dione by Memory of Chirality

“…This can be related to the Chan reaction, [20] a base-induced rearrangement of an acyloxyacetate to a 2-hydroxy-3-oxo ester, and the N Ǟ C acyl migration of an acyclic imide, [21] two rare tools used in the total syntheses of aplasmomycin, [22] boromycin, [23] rapamycin, [24] diazonamide A [25] and taxol. [26] In order to explore this original reactivity, bis-Boc BZD 2 was subjected to other bases (Table 1).…”

Esterification of borate with NAD+and NADH as studied by electrospray ionization mass spectrometry and11B NMR spectroscopy

“…Boron‐containing compounds have been isolated from various biological sources that exhibit biological properties. These include boromycin,1–3 aplasmomycin,4, 5 tartrolon,6–8 the autoinducer 2, a bacterial quorum sensing pheromone9 and rhamnogalacturonan II (RG‐II) dimers in plants 10, 11. In aqueous solution boron exists as either boric acid (B(OH) 3 ) or borate (B(OH) 4 − ) ions [Eqn (1)].…”