抄録
Aiming to overcome several inefficient aspects of ordinary chemical resolution of racemic compound, we have developed the new methodology which recommends utilization of symmetrically functionalized meso-compound as a resolution substrate in place of racemic compound. As shown in Scheme I, when meso-compound(1) is monofunctionalized by a chiral compound and each of the formed diastereomers (2 and 3), separable by fractional recrystallization or chromatography, is submitted to further chemical elaboration including protective group transposition, it is theoretically possible to convert the total amount of the starting material into one requisite optically pure synthetic intermediate(6 or 7) by selecting synthetic operations. By employing this novel concept, the optically pure prostaglandin intermediate(Scheme II, (-)-9) has been prepared from the meso-diol(8) via the two diastereomers(10 and 11) which are produced by the reaction of 8 and N-methanesulfonyl-(S)-phenylalanyl chloride. In a similar manner, another optically pure prostaglandin intermediate(Scheme III, (-)-19) and optically pure steroid intermediate(Scheme IV, (-)-25) have been successfully synthesized from the corresponding meso-diols(18 and 24), respectively. These successful results seem to clearly disclose wide generality of the exploited novel methodology.
