The first, enantiospecific total syntheses of pyranonaphthoquinone antibiotics, nanaomycinsD 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]pyran-3,4-diol, which has been derived from L-rhamnose via condensation of
第一个,吡喃萘醌抗生素,nanaomycins D 和 A 及其对映异构体,kalafungin 和 4-deoxykalafunginic 酸的对映特异性全合成是通过来自常见光学活性中间体 (1S,3RS,4S)-3 的“对映发散”策略描述的, 4-dihydro-5,9,10-trimethoxy-1-methyl-1H-naphtho[2,3-c]pyran-3,4-diol,由L-鼠李糖通过4-甲氧基-3缩合得到(苯基磺酰基)-1(3H)-异苯并呋喃酮和甲基 3,4,6-三脱氧-α-L-甘油-己基-3-烯吡喃糖苷-2-酮糖。
The first total synthesis and structural determination of (+)-BE-52440A
The first total synthesis and structural determination of (+)-BE-52440A have been achieved by enantiodivergent synthesis. S-Bridging dimerization including SN2 epoxy-opening reaction of tetrasubstituted epoxide 2 with sodium sulfide has been achieved in excellent yield with high regioselectivity. The structure of (+)-BE-52440A was determined to be the dimer of kalafungin type pyranonaphthoquinone.
(+)-BE-52440A的第一个全合成和结构测定已通过对映发散合成实现。已经以优异的产率和高的区域选择性实现了包括四取代的环氧化物2与硫化钠的S N 2环氧-开环反应的S桥二聚化。确定(+)-BE-52440A的结构为卡拉芬净型吡喃并萘醌的二聚体。