Danishefsky’s total synthesis

Scheme 37 Regioselective RCM of tetraene 191 in Danishefsky s total synthesis of migras-tatin (192) [95]...

Scheme 48 Diene-ene RCM in Danishefsky s total synthesis of radicicol (230) [108] and its cycloprop a-analog 228 [109,110]...

Danishefsky s total synthesis of 317 and its chlorine free precursor monocillin I 316 features an RCM reaction with a substrate 310 that in addition to a dithiane protective group contains a vinyl epoxide and a diene moiety at... 

Danishefsky s Total Synthesis Carbobicydic Core by Aldol and Heck Reactions... 

Fig. 4. Danishefsky s total synthesis formation of cyclobutanone, sulfenylation, and successive oxidation reactions. DME = 1,2-dimeth-oxyethane, TBAF = tetra-n-butylammonium fluoride, NMO = A/-methyl-morpholine-N-oxide.

Danishefsky s total synthesis of vineomycinone B2 methyl ester [31] (Scheme 12.40) involves the construction of the sugar moiety possessing a C-glycosidic bond by a hetero Diels-Alder... 

Danishefsky s total synthesis features aldol coupling of the C10-C27 segment and A-[2-(phenylsulfoxy)acetyl] pipecolate, subsequent esterification with the C28-C42 segment, and highly novel intramolecular macroaldolization at the C27 and C28 positions (Fig. 6). 

Danishefsky s total synthesis of avermectin (3a) was accomplished via an aldol reaction to join the northern and southern segments, intramolecular Nozaki aldol cyclization [138] to construct the southern ring system, Mukaiyama macro-lactonization, deconjugation to the C3-C4 double bond, and NIS-mediated gly-cosidation (Fig. 7). 

Scheme 15. Final stages and completion of Danishefsky s total synthesis of dynemicin A (1).

Scheme 27. Danishefsky s total synthesis of epothilone B (2) using molybdenum olefin-metathesis catalyst 11. ...

Another impressive illustration of the Eschenmoser-Claisen rearrangement is displayed in the pathway leading to the Danishefsky s total synthesis of phomoidride... 

At first, as shown in Scheme 5, we pursued the synthesis of intermediate 28, a substrate for the key [2,3]-Wittig rearrangement, starting from known enan-tiomerically pure 14 [17]. The route to allyl alcohol 13 from 14 has been established (30% overall yield in 11 steps) in Danishefsky s total synthesis of ( )-2 (cf. Section Total Synthesis of ( )-Sesquicillin [Zhang and Danishefsky] ) [13]. Therefore, we decided to follow the Danishefsky s route with some improvements of the reaction steps and conditions (cf. 29—>30—>18, 19- [31] 20), which allowed an increase in the total... 

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