C 2 -对称氮丙啶(2S,3S)-1-卤素-2,3-二甲基氮丙啶1a,b和(2S,3S)-1-卤素-2的N-氯(a)和N-溴(b)衍生物,获得3-双(烷氧基羰基)氮丙啶2a,b和3a,b。卤代氮丙啶 1a、b 是“纯”N-卤代氮丙啶发色团的一个例子,它在 260-300 nm 范围内具有第一棉花效应 (CE)。提供了将第一个 CE 符号与发色团的立体化学环境联系起来的象限规则。卤代氮丙啶羧酸酯是 N-卤代氮丙啶发色团的一种特殊情况。这些化合物的 CD 光谱中 220-230 nm 处的第二个 CE 符号遵循反向象限规则
Chiroptical properties of C2-symmetric N-haloaziridines. Chiral rules for the N-haloaziridine chromophore
作者:G. V. Shustov、A. V. Kachanov、V. A. Korneev、R. G. Kostyanovsky、A. Rauk
DOI:10.1021/ja00075a048
日期:1993.11
Haloaziridines 1a,b are an example of the «pure» N-haloaziridine chromophore which has the first Cotton effect (CE) in the region of 260-300 nm. A quadrant rule which connects the first CE sign with the stereochemical environment of the chromophore is offered. Haloaziridinecarboxylic esters are a specific case of the N-haloaziridine chromophore. The second CE sign at 220-230 nm in the CD spectra of these
C 2 -对称氮丙啶(2S,3S)-1-卤素-2,3-二甲基氮丙啶1a,b和(2S,3S)-1-卤素-2的N-氯(a)和N-溴(b)衍生物,获得3-双(烷氧基羰基)氮丙啶2a,b和3a,b。卤代氮丙啶 1a、b 是“纯”N-卤代氮丙啶发色团的一个例子,它在 260-300 nm 范围内具有第一棉花效应 (CE)。提供了将第一个 CE 符号与发色团的立体化学环境联系起来的象限规则。卤代氮丙啶羧酸酯是 N-卤代氮丙啶发色团的一种特殊情况。这些化合物的 CD 光谱中 220-230 nm 处的第二个 CE 符号遵循反向象限规则
A practical synthesis of D-Malate esters from L-tartrate esters
作者:Yun Gao、Charles M. Zepp
DOI:10.1016/s0040-4039(00)79709-7
日期:1991.7
D-malate esters were synthesized in one-pot from L-tartrate esters in 70-80% overall yields via the corresponding tartrate cyclic sulfites.
STINSON, STEPHEN, CHEM. AND ENG. NEWS, 66,(1988) N 44, C. 22
作者:STINSON, STEPHEN
DOI:——
日期:——
Efficient synthesis of chiral α,β-epoxyesters via a cyclic sulfate intermediate
作者:Linli He、Hoe-Sup Byun、Robert Bittman
DOI:10.1016/s0040-4039(98)00190-7
日期:1998.4
An efficient synthesis of chiral α,β-epoxyester 1 from chiral 2,3-dihydroxyester 2 has been developed. Ester 2 is converted to the corresponding cyclic sulfate 3, which is opened with either LiBr in THF or Bu4NBr in acetone at rt to furnish 2-bromo-3-hydroxyester 4. Treatment of 4 with K2CO3 in methanol at low temperature gives α,β-epoxyester 1 in excellent overall yield and in the same ee as in the
手性α,β环氧酯的有效的合成1从手性2,3- dihydroxyester 2已经研制成功。将酯2转化为相应的环状硫酸盐3,将其在室温下用THF中的LiBr或在丙酮中的Bu 4 NBr打开,以提供2-溴-3-羟基酯4。在甲醇中在低温下用K 2 CO 3处理4,得到的α,β-环氧酯1的总收率极好,且ee与起始二醇相同。