[GRAPHICS]An effective total synthesis of (-)-callystatin A (1), member of the leptomycin family of antibiotics, has been achieved. The synthesis features Evans extended aldol methodology to construct the northern polypropionate subunit and two separate Julia olefinations to assemble the conjugated dienes. The total synthesis proceeded in 2.3% overall yield with the longest linear sequence of 15 steps.
Diastereoselective Chelation-Controlled Additions to β-Silyloxy Aldehydes
作者:Gretchen R. Stanton、Meara C. Kauffman、Patrick J. Walsh
DOI:10.1021/ol301354w
日期:2012.7.6
A general diastereoselective method for the addition of dialkylzincs and (E)-di- and (E)-trisubstituted vinylzinc reagents to β-silyloxy aldehydes is presented. This method employs alkyl zinc triflate and nonaflate Lewis acids and affords chelation-controlled products (6:1 to > 20:1 dr).
介绍了将二烷基锌和 ( E )-二-和 ( E )-三取代的乙烯基锌试剂添加到 β-甲硅烷氧基醛的一般非对映选择性方法。该方法使用烷基三氟甲磺酸锌和九氟甲磺酸锌路易斯酸,并提供螯合控制产品(6:1 至 > 20:1 dr)。
A Highly Convergent and Biomimetic Total Synthesis of Portentol
作者:Bichu Cheng、Dirk Trauner
DOI:10.1021/jacs.5b10009
日期:2015.11.4
An efficient total synthesis of the unusual polyketide portentol is reported. Three boron aldol reactions were used to assemble the linear carbon chain of the natural product, which contains two challenging anti-anti stereotriads. A biomimetic double cyclization cascade, triggered by an oxidation, then afforded portentol and its known dehydration product, anhydroportentol. The biosynthesis of portentol