手征性硫代磷酸及其衍生物的研究(Ⅱ)——旋光活性的O-乙基O-苯基硫代磷酸及其硫(醇)代酯的绝对构型

STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES (Ⅱ) -ABSOLUTE CONFIGURATIONS OF THE OPTICAL ACTIVE O-ETHYL O-PHENYL PHOSPHOROTHIOIC ACID AND ITS THIOL-ESTERS

O一乙基-O-苯基硫代磷酸(1)及其硫(醇)代酯(2)的绝对构型可由以下两步反应确定(见图1)。即,(-)-(2)的氯化和(-)-O-乙基-O-苯基磷酰氯(3)的酯化反应。由(-)-(2)→(-)-(3)氯化反应的立体化学过程已a.R′=CH3b.R′=n-prc.R′=CH2CH2OC2H5经证明,不管是使用氯气还是使用SO2Cl2为氯化剂,均为磷原子构型保留,由(-)-(3)生成(-)-O-乙基-O-甲基O-苯基磷酸酯(4)的反应则使构型翻转。同时(-)-(4)构型已知为(R)-(+)-(4)、(S)-(-)-(4),所以(+)-(1)和(-)-(2)的绝对构型可确定为:(R)-(+)-(1)和(R)-(-)-(2)。这一结果与X-射线衍射法所得结果完全一致。

The absolute configurations of O-ethyl O-phenyl phosphorothioic acid ( 1) and its thiol-esters (2) were established by the following reactions (Scheme l.):the chlorination of (-)-(2)and esterification of (-)-O-ethyl O-phenyl phosphorochloride;(3) It has been confirmed that the chlorination of (-)-(2) either with Cl_(2) or SO_(2) Cl_(2) proceeds with retention of the configuration, and the esterification of(-)-(3) forms (-)-O-ethyl O-methyl O-phenyl phosphate;(4) proceeding with complete inversion of its configuration.■Since the absolute configurations of (-)-(4) are kno wn as. (S)-(-)-(4), (R)-( + )-(4), the absolute configurations of ( + )-(1) and (-)-(2 ) should be (R)-( + )-(l) and (R)-(-)-( 2),respectively. This result consists with that one obtained by X-ray diffraction method.