11048-15-0Relevant articles and documents
Efficient synthesis of (+)-kalafungin and (-)-nanaomycin D by asymmetric dihydroxylation, oxa-pictet-spengler cyclization, and H2SO 4-mediated isomerization
Fernandes, Rodney A.,Brückner, Reinhard
, p. 1281 - 1285 (2005)
The pyranonaphthoquinone antibiotics and antitumor agents (+)-kalafungin (1) and (-)-nanaomycin D (3 = ent-1) were synthesized from 1,5-napthalenediol (13) in 11 steps. Stereocontrol was high: 99.5 ee/93% diastereoselectivity for 1, 98.5% ee/94% diastereoselectivity for 3. Enantiocontrol was achieved by the asymmetric dihydroxylation of the β,γ-unsaturated ester 9. Diastereocontrol was realized in the final step by an almost complete epimerization in H2SO4.
A chiron approach to the total synthesis of (-)-juglomycin A, (+)-kalafungin, (+)-frenolicin B, and (+)-deoxyfrenolicin
Fernandes, Rodney A.,Chavan, Vijay P.,Mulay, Sandip V.,Manchoju, Amarender
, p. 10455 - 10460 (2012)
A general, efficient, and common strategy for the synthesis of (-)-juglomycin A, (+)-kalafungin, (+)-frenolicin B, and (+)-deoxyfrenolicin is reported here. The strategy involves the synthesis of a key building block alkyne from a cheap chiral pool material, d-glucono-δ-lactone, Doetz benzannulation, oxa-Pictet-Spengler reaction, and H2SO 4-mediated epimerization.
The divergent asymmetric synthesis of kalafungin, 5-epi-frenolicin B and related pyranonaphthoquinone antibiotics
Donner, Christopher D.
, p. 377 - 386 (2013/01/15)
A divergent, asymmetric method for the synthesis of pyranonaphthoquinones is reported. The synthetic strategy applies a Staunton-Weinreb annulation between substituted ortho-toluates and the (R)-pyran-2-one 7 to construct the key naphthopyranone intermediates. Stereoselective introduction of either a methyl or propyl C5 alkyl substituent by use of Grignard addition/silane- mediated reduction and a sequence of oxidations gave a series of pyranonaphthoquinones including kalafungin 1, 5-epi-9-methoxykalafungin 34 and 5-epi-frenolicin B 24.
Total synthesis of (+)-kalafungin using a tandem Michael-Dieckmann approach
Donner, Christopher D.
, p. 8888 - 8890 (2008/03/30)
A stereoselective synthesis of the antibiotic kalafungin 1 is reported. A key step involved the tandem Michael-Dieckmann reaction between methyl 2-methoxy-6-methylbenzoate 11 and the α,β-unsaturated lactone (R)-6-(2-(tert-butyldimethylsilyloxy)ethyl)-4-methoxy-5,6-dihydropyran-2-one 10, which was prepared from (S)-aspartic acid. The C5 alkyl substituent was introduced by the use of methylmagnesium bromide and subsequent stereoselective reduction. A sequence of oxidations followed by acid-catalyzed epimerization delivered (+)-kalafungin 1.
Enantiodivergent total syntheses of nanaomycins and their enantiomers, kalafungins
Tatsuta,Akimoto,Annaka,et al.
, p. 1699 - 1706 (2007/10/02)
The first, enantiospecific total syntheses of pyranonaphthoquinone antibiotics, nanaomycins D and A, and their enantiomers kalafungin and 4-deoxykalafunginic acid, are described by an 'enantiodivergent' strategy from a common optically active intermediate, (1S,3RS,4S)-3,4-dihydro-5,9,10-trimethoxy-1-methyl-1H-naphtho[2,3-c]pyr an-3,4-diol, which has been derived from L-rhamnose via condensation of 4-methoxy-3-(phenylsulfonyl)-1-(3H)-isobenzofuranone and methyl 3,4,6-trideoxy-α-L-glycero-hex-3-enopyranosid-2-ulose.
