Diazomethane was generated (from 5 g of Diazald) and distilled together with ether into a mixture of 2-benzyl 3-methyl(2S,3S,5S)-1-benzyl-5-hydroxypiperidine-2,3-dicarboxylate (0.60 g, 0.0016 mol) and around 1 g of silica gel in 10 mL of ether. After distillation, the mixture was stirred at rt overnight. The mixture was diluted with methylene chloride, filtered to remove silica gel. The filtration was concentrated to dry and the resulting residue was applied on column, eluting with 0 to 40% EtOAc in Hexane, to yield the methyl ether compound (20 mg, 3.2%). MS (ESI): (M+H)+=398.1.
