(2R)-2-[(4R,5R)-2,2,5-trimethyl[1,3]dioxan-4-yl]propionaldehyde 、 (E)-4-Methylsulfanyl-3-pyrrolidin-1-yl-but-2-enoic acid methyl ester 在
lithium diisopropyl amide 作用下,
以
四氢呋喃 为溶剂,
以75%的产率得到(5R,6S)-5-Methylsulfanyl-4-pyrrolidin-1-yl-6-[(R)-1-((4R,5R)-2,2,5-trimethyl-[1,3]dioxan-4-yl)-ethyl]-5,6-dihydro-pyran-2-one