Total Synthesis of Efomycine M

Abstract

Two‐directional synthesis: Key steps in the first total synthesis of the anti‐inflammatory agent efomycine M (1) are a two‐directional C11–C12 chain elongation and an early‐stage dimerization reaction. The central stereopentad is synthesized by a highly stereoselective sequence consisting of an anti‐aldol reaction and a diastereoselective reduction.

Gombapyrones E and F, New α-Pyrone Polyenes Produced by Streptomyces sp. KMC-002

“…In addition, polyketide natural products have provided many pharmaceutical lead compounds such as polyene-polyol macrocyclic lactones, nystatin and amphotericin B [ 18 , 19 , 20 , 21 , 22 ]. Because of their large structural diversity and varied biological functions, it is an undeniable fact that polyketide natural products are one of the attractive groups for developing useful chemicals as therapeutic approaches or as synthetic challenges [ 23 , 24 , 25 ]. In our preliminary screening for discovery of new polyketides produced by abandoned mine-derived actinomycetes, two new polyene-polyketides, gombapyrone E ( 1 ) and F ( 2 ), were isolated from organic extract of Streptomyces sp.…”

Approach to the synthesis of the C1–C11 and C14–C18 portion of Leucascandrolide A

“…9 Exposure of aldehyde 9 to the vinylogous Horner-Wadsworth-Emmons reagent 10 and LiOH as base gave the desired dienoate 11 (68%), 10 which could be converted into the desired syn/anti -1,3,5-triol by our three step asymmetric hydration protocol. Thus, treating the E , E -dienoate 11 to the typical Sharpless asymmetric dihydroxylation conditions (5% OsO 4 , 6% (DHQ) 2 PHAL, K 3 FeCN 6 , MeSO 2 NH 2 ), provided diol 12 in good yield (71%) and as a single diastereomer.…”

An enantioselective catalytic approach to syn deoxypropionate units combining asymmetric Cu-catalyzed 1,6- and 1,4-conjugate addition

“…Using isobutyraldehyde 10c and the conditions reported for the extended HWE reaction 11 with the oxoester analogue of 11, 12 the product 7c was obtained in low, poorly reproducible yields but excellent E/Z-selectivity (Table 1, entry 1). The use of LHMDS as a base improved the yield slightly but still gave poorly reproducible results (entry 2).…”