Ingramycin synthesis

Tanner s ingramycin synthesis is based on the coupling of three segments 146, 148 and 150 by using the sulfone anions. 

Metalated sulfones with 3 leaving groups can be generated at low temperature and trapped with electrophiles. For example the a-lithio sulfone (76 Scheme 27) was prepared by metalation with LDA at -90 C in 9 1 THF-HMPA and condensed with aldehyde (75). Acetylation of the adduct followed by reductive elimination gave an intermediate in the synthesis of the antibiotic ingramycin. ... 

Total syntheses of the following antibiotics and/or their aglycones are dealt with methymycin, erythromycin, pikromycin, oleandomycin, ingramycin (albo-cycline), carbomycin B, leucomycin A3 (josamycin), tylosin, mycinamicins, rosaramicin, A26771B and elaiophylin (azalomycin B). Since the total synthesis of the macrolide-like immunosuppressant FK-506 has been recently reported, it is also reviewed here. Today, erythromycin A, oleandomycin, leucomycin A3 (josamycin), tylosin and mycinamicin II are clinically important antibiotics. 

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