Enantioresolution of Alcohols and its Application to Organic Synthesis

(S)-()-2-甲氧基-2-(1-萘基)丙酸，即所谓的(S)-()-MαNP酸，由原田信之教授和我本人共同设计，具有两种作用：一是对仲醇进行非对映异构体分离，二是同时测定醇的羟基的绝对构型。我们已经注意到我们的新型手性助剂的这些作用，并报道了使用该手性助剂合成各种光学活性芳基甲醇和二元甲醇。我们还重点研究了从1890年S开始研究的芹菜油中的主要香料4-丁基苯酞，并用不对称合成机理推测了其绝对构型。香料的结构最终确定为(S)-(-)-4-丁基苯酞。我们还成功地合成了松茸香气的两个对映体“松茸醇”。众所周知，含脂肪长链的醇的对映体拆分和羟基绝对构型的测定是困难的。目前还没有此类醇的不对称合成的报道。最近，我们用油酸制备的36个碳成功地拆分了这类醇，并测定了其羟基的绝对构型。这是一种合成含长链脂肪族取代基生物活性醇类化合物的有效方法。

(S)-(+)-2-Methoxy-2-(1-naphthyl)propionic acid so-called (S)-(+)-MαNP Acid, which was devised together by Professor Nobuyuki Harada, Dr shunsike Kuwahara and myself, has two roles ; one is diastereomeric separation of secondary alcohols and the other is simultaneous determination of absolute configuration of the hydroxyl group of the alcohols. We have paid our attention to these roles of our new chiral auxiliary, and reported syntheses of variety kinds of optical active aryl methanol and diary methanol, using the chiral auxiliary. We also focused on 4-butylphthalide known as a major fragrance of celery oil determined whose research started in 1890's. The absolute configuration of 4-butylphthalide has been speculated by the mechanism of asymmetric synthesis. The structure of the fragrance was finally determined as (S)-(-)-4-butylphthalide. We also succeeded in the synthesis of two enantiomers of the fragrance of matsutake mushroom known as "matsutakeol".It is well known that enantioresolution of alcohols with aliphatic long-chaine and the determination of absolute configuration of the hydroxyl groups is difficult. There has been also no report of asymmetric synthesis of such alcohols. We, recently, succeeded in the enantioresolution of such alcohols with 36 carbons prepared from oleic acid and determination of absolute configuration of its hydroxyl group. This is a promising methodology to synthesis of biological active alcohols consists of long-chain aliphatic substituents.