(4bS,4cR,8aR,8bS)-8-((2R,4S,5R)-4-Acetoxy-5-hydroxymethyl-tetrahydro-furan-2-yl)-2-hydroxy-3-hydroxymethyl-4c-methyl-5,7-dioxo-4c,5,6,7,8,8a-hexahydro-4bH-9-oxa-6,8-diaza-benzo[3,4]cyclobuta[1,2-a]indene-8b-carboxylic acid methyl ester 在
2,2,6,6-tetramethyl-piperidine-N-oxyl 、
氧气 、
copper(l) chloride 作用下,
以
N,N-二甲基甲酰胺 为溶剂,
反应 6.0h,
以70%的产率得到(4bS,4cR,8aR,8bS)-8-((2R,4S,5R)-4-Acetoxy-5-hydroxymethyl-tetrahydro-furan-2-yl)-3-formyl-2-hydroxy-4c-methyl-5,7-dioxo-4c,5,6,7,8,8a-hexahydro-4bH-9-oxa-6,8-diaza-benzo[3,4]cyclobuta[1,2-a]indene-8b-carboxylic acid methyl ester