Aldol condensation reactions of tricarbonyliron complexes. Towards building blocks for the synthesis of carbomycin B/tylosin macrolide antibiotics and fluorinated analogs
M. Franck-neumann et al., Aldol condensation reactions of tricarbonyliron complexes. Towards building blocks for the synthesis of carbomycin B/tylosin macrolide antibiotics and fluorinated analogs, TETRAHEDR L, 41(21), 2000, pp. 4219-4222
Tricarbonyliron complexes of alpha-methoxyheptadienone 3 and octadienone 8
were reacted as silyl enol ethers with protected beta-hydroxypropanal and T
iCl4, to give the syn-syn aldol condensation products 4 and 11 as major, is
olated diastereomers (61 and 45%), Products 4 and 11 were converted into ke
y intermediates of previous total syntheses of carbonolide B and tylonide,
in a few steps, including the iron-directed reduction to syn diols and part
ial ozonolysis. The same methodology was used for the high yielding synthes
is of a monofluorinated analog. (C) 2000 Elsevier Science Ltd. All rights r
eserved.