本論文以D-(–)-2-苯甘胺酸61 作為含有光學輔助基的起始物，經由官能基轉換與修飾後，環化生成噁嗪酮(oxazinone) 59；利用化合物59製備烯醇陰離子進行不對稱碳-碳烷化後，碳-氮烷化並合環形成化合物58，再經由各種不同的親電子基(electrophile)進行第二次烷化與氫化之後，就可以得到在α-碳上有不同取代基的六氫菸鹼酸57。 The synthesis of 57 is based on the chiral oxazinone 59 as a chiral glycine enolate synthon. Asymmetric alkylation of 59 with 1,4-diiodobutane, deprotection and cyclization gave the 4-phenylhexahydropyrido[2,1-c][1,4] oxazin-1-one. Both enantiomers of pipecolic acid and 2-alkyl pipecolic acids were prepared by the epimerization or the second alkylation of 58 followed by hydrogenation.
