Stereoselective Preparation of 3-Amino-2-fluoro Carboxylic Acid Derivatives, and Their Incorporation in Tetrahydropyrimidin-4(1H)-ones, and in Open-Chain and Cyclic β-Peptides
作者:Tomohiro Yoshinari、François Gessier、Christian Noti、Albert K. Beck、Dieter Seebach
DOI:10.1002/hlca.201100340
日期:2011.11
with N,N‐dibenzyl‐2‐amino‐3‐hydroxy and 3‐amino‐2‐hydroxy carboxylic acid esters is discussed (Fig. 1). The fluoro‐β‐amino acid residues have been incorporated into pyrimidinones (11–13; Fig. 2) and into cyclic β‐tri‐ and β‐tetrapeptides 17–19 and 21–23 (Scheme 3) with rigid skeletons, so that reliable structural data (bond lengths, bond angles, and Karplus parameters) can be obtained. β‐Hexapeptides
(2的制备小号,3小号) -和(2 - [R,3小号)-2-氟和(3小号)-2,2-二氟-3-氨基羧酸衍生物,1 - 3,选自丙氨酸,缬氨酸,亮氨酸,苏氨酸,和β 3 H-丙氨酸(方案1和2,表)进行说明。讨论了(二乙基氨基)三氟化硫(DAST)与N,N-二苄基-2-氨基-3-羟基和3-氨基-2-羟基羧酸酯的立体化学过程(图1)。氟β氨基残基已被纳入嘧啶酮(11 - 13 ;图2)并进入环状β -三-和β -tetrapeptides 17 - 19和21 - 23(方案3)具有刚性骨架,从而使可靠的结构数据(可以获得键长,键角和Karplus参数)。β -Hexapeptides的Boc [(2-小号) - β 3 hXaa(α F)] 6 OBN和Boc [ β 3 hXaa(α,αF 2)] 6 -OBn,24 – 26,具有Ala,Val和Leu的侧链,已经合成(方案4),并讨论了