Efficient Synthesis of (+)-Kalafungin and (-)-Nanaomycin D by Asymmetric Dihydroxylation, Oxa-Pictet-Spengler Cyclization, and H2SO4-Mediated Isomerization
The divergent asymmetric synthesis of kalafungin, 5-epi-frenolicin B and related pyranonaphthoquinone antibiotics
作者:Christopher D. Donner
DOI:10.1016/j.tet.2012.10.012
日期:2013.1
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
Total synthesis of (+)-kalafungin using a tandem Michael–Dieckmann approach
作者:Christopher D. Donner
DOI:10.1016/j.tetlet.2007.10.058
日期:2007.12
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
A Chiron Approach to the Total Synthesis of (−)-Juglomycin A, (+)-Kalafungin, (+)-Frenolicin B, and (+)-Deoxyfrenolicin
作者:Rodney A. Fernandes、Vijay P. Chavan、Sandip V. Mulay、Amarender Manchoju
DOI:10.1021/jo3019939
日期:2012.11.16
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, Dötzbenzannulation, oxa-Pictet-Spengler reaction, and H2SO4-mediated epimerization.
此处报道了合成(-)-珠红霉素A,(+)-卡拉芬净,(+)-肾上腺素B和(+)-脱氧肾上腺素的通用,有效且通用的策略。该策略涉及由廉价的手性池材料,d-葡萄糖酸-δ-内酯,Dötz苯环化,oxa-Pictet-Spengler反应和H 2 SO 4介导的差向异构化合成关键的结构单元炔烃。