The synthesis of diastereo-enriched substituted
(4S)-4-isopropyl-2-(2,2′-binaphthalen-1-yl)-4,5-dihydrooxazoles
from substituted 2-naphthalenylmagnesium bromides and
(4S)-4-isopropyl-2-(2-methoxynaphthalen-1-yl)-4,5-dihydrooxazole (4) and
(4S)-4-isopropyl-2-(2,3-dimethoxynaphthalen-1-yl)-4,5-dihydrooxazole
(5) is described. The product oxazolines were converted into a number of
derivatives and the free energy barriers to internal rotation of several of
these derivatives were determined. The determination of the X-ray crystal
structures and the c.d. spectra of
(S,1S)-N-[2-hydroxy-1-(isopropyl)ethyl]-3-methoxy-1′,N-dimethyl-2,2′-binaphthalene-1-carboxamide
(22) and
(R,4S)-4-isopropyl-3-methyl-2-(1′,2′,4′-trimethyl-2,2′-binaphthalen-1-yl)-4,5-dihydrooxazolium
iodide (38) allowed the assignment of the absolute configurations of all the
synthetic 2,2′-binaphthalenes by comparison of their c.d. spectra
with those of compounds (22) and (38).
合成非对映富集取代的
(4S)-4-异丙基-2-(2,2′-联萘-1-基)-4,5-二氢恶唑
从取代的 2-萘基溴化镁和
(4S)-4-异丙基-2-(2-甲氧基萘-1-基)-4,5-二氢恶唑 (4)和
(4S)-4-异丙基-2-(2,3-二甲氧基萘-1-基)-4,5-二氢恶唑
(5) 进行了描述。产品噁唑啉被转化为多种
衍生物,并测定了其中几种衍生物内旋转的自由能垒。
衍生物的内旋转自由能障。X 射线晶体结构和
结构和 c.d. 光谱。
(S,1S)-N-[2-羟基-1-(异丙基)乙基]-3-甲氧基-1′,N-二甲基-2,2′-联萘-1-甲酰胺 (22) 和
(22) 和
(R,4S)-4-异丙基-3-甲基-2-(1′,2′,4′-三甲基-2,2′-萘-1-基)-4,5-二氢恶唑鎓碘化物 (38)
碘化物 (38) 的绝对构型。
通过比较 2,2′-联萘的 c.d. 光谱和化合物(22)的 c.d. 光谱,可以确定所有合成 2,2′-联萘的绝对构型。
与化合物 (22) 和 (38) 的 c.d 光谱进行比较,从而确定了所有合成 2,2′-萘的绝对构型。