Chiral pool synthesis of trans-(2S3S)-3-hydroxyproline and castanodiol from S-pyroglutamic acid.
作者:Claus Herdeis、Hans Peter Hubmann、Hermann Lotter
DOI:10.1016/s0957-4166(00)80492-9
日期:1994.1
The Pyroglutamic acid derivative 1 was converted through several steps into Castanodiol 9 and 2S,3S-3-Hydroxyproline 11. Key steps of the reaction sequence were the stereoselective epoxidation of 1 to 2 and the regioselective ring opening of 2 to 3. BH3.S(CH3)(2) reduction of the amide group of 3 and 4 resulted in a concomitant transformation of the acetal moiety into the N-benzyl protecting group. The air sensitive 5 and 6, were transformed to the stable N-Boc prolinol derivatives 7 and 8. Deprotection of 8 provided 9, while oxidation of 8 gave the protected proline derivative 10. Deprotection of 10 furnished enantiopure 2S,3S-3-Hydroxyproline 11.