Title: APPROACHES TO THE SYNTHESIS OF METHYMYCIN
نویسنده
چکیده
Several approaches to the synthesis of methymycin were investigated. Segment A (39), containing functionality corresponding to C-9, 10, and 11 of methynolide was made in six steps from propionaldehyde in an overall yield of 37%. Oxidation of 34 with silver nitrate gave 35 which, upon hydroxylation with hydrogen peroxide, gave the erythro isomer of dihydroxy acid 36. This acid was resolved with brucine and its absolute configuration determined by Horeau's method. The (+) acid was found to have R,R configuration. This substance was converted to its acetonide (+)-37, which was reduced with lithium aluminium hydride to give (+)-38. Oxidation of (+)-38 with Collins' reagent gave (+)-39. An approach to the B segment (31), corresponding to
منابع مشابه
Total synthesis of methymycin.
Methynolide and 10-epi-methynolide were synthesized from the necessary segments, which were prepared by the addition of Grignard reagents to the corresponding alpha-alkoxyketones utilizing 1,2-stereochemical selection based on Cram chelation control. Ring-closing metathesis, as the key reaction, was carried out to combine the segments for the synthesis of methynolide and 10-epi-methynolide. The...
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تاریخ انتشار 2013