Yield:862847-44-7 100%

Reaction Conditions:

with triethylamine in ethanol;Reflux;

Steps:

Boc-Lys-OH (1.0 gr, 4.06 mmol) was dissolved in 10 ml of EtOH. Then 1-(4,4-Dimethyl-2,6-dioxocyclohex-1-ylidene)-3-methylbutyl (ivDde) was added (1.15 ml, 5.28mmol) followed by the addition of Et₃N ( 847.2 μL, 6.09 mmol). The reaction mixture was heated to reflux and stirred ON. The reaction was monitored by TLC (EtOAc:MeOH, 9:1). Upon completion the reaction mixture was diluted with EtOAc and washed with HCl 1M. The organic layer was separated and dried over MgSO₄,filtered and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica gel (EtOAc: MeOH 9:1, 1% AcOH) to afford compound 1d' (1.84 gr, quant.) as a white solid.

References:

Kisin-Finfer, Einat;Ferber, Shiran;Blau, Rachel;Satchi-Fainaro, Ronit;Shabat, Doron [Bioorganic and Medicinal Chemistry Letters,2014,vol. 24,# 11,p. 2453 - 2458] Location in patent:supporting information