制备 de dioxyde-2,2 de dioxathiolannes-1,3,2(I) a partir deglycols et 反应 脱硫酸盐 cycliques(I) avec divers 亲核试剂 (H - , N 3 - , F - , PhCO 2 - , NO 3 − , SCN − , PhCH 2 − )
制备 de dioxyde-2,2 de dioxathiolannes-1,3,2(I) a partir deglycols et 反应 脱硫酸盐 cycliques(I) avec divers 亲核试剂 (H - , N 3 - , F - , PhCO 2 - , NO 3 − , SCN − , PhCH 2 − )
The two isomers (2S, 3S) and (2S, 3R) of 3-fluoro-D-aspartic acid were synthesized by two independent routes both starting from D-tartaric acid esters.
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。