All four possible stereoisomers of lactone II isolated from
Streptomyces sp. Go 40/10, an autoregulator, have been efficiently
synthesized in a stereoselective manner starting from (S)-malic
acid and sorbic acid, and the absolute configuration was determined to be
2S, 3S, 9R, 10S.
以(S)-苹果酸和山梨酸为起始原料,以立体选择性方式高效合成了从自律调节链霉菌 Go 40/10 分离得到的内酯 II 的所有四种可能的立体异构体,并确定其绝对构型为 2S、3S、9R、10S。
A simple synthesis of Ω[(E)CHCH]gly dipeptide isosteres via reductive elimination of γ-oxygenated α,β-enoates with alkenylcopper reagents
Readily available protected forms of δ-amino-γ-msyloxy-α,β-enoates can be converted to protecteddipeptideisosteres, Ω[(E)CHCH]Gly, in high yields by reduction with alkenylcopper reagents.
Very high chemoselective, regioselective, and E-stereoselective 1,3-chirality transfer involving reaction of acyclic (E)- and (Z)-.gamma.-mesyloxy .alpha.,.beta.-enoates and organocyanocopper-trifluoroborane reagents. Efficient synthetic routes to functionalized chiral .alpha.-alkyl (E)-.beta.,.gamma.-enoates and (E)-allylic alcohols with high optical purity
Remarkable difference in reactivity of ordinary vinylcopper reagents and vinylzinc halide containing a copper salt towards γ-mesyloxy-α, β-enoates. Synthesis of homochiral 1,4-dienes
Whereas the reaction of gamma-mesyloxy alpha,beta-enoates with vinyl-Cu(CN)M or (vinyl)2Cu(CN)M2 (M = Li or MgX) yielded a reduction product with an (E)-double bond at the beta,gamma-position, treatment of the same substrates with ''higher order'' zinc cuprate reagents or vinyl-ZnCl by the addition of catalytic amount of Cu(I) or Cu(II) salt afforded alpha- and gamma-vinylation products. Both vinylation products were stable 1,4-diene derivatives that are only more difficulty accessed by more traditional means.
IBUKA TOSHIRO; NAKAO TOMIO; NISHII SHINJI; YAMAMOTO YOSHINORI, J. AMER. CHEM. SOC., 108,(1986) N 23, 7420-7422