Lithium Hexamethyldisilazide → 5(S)-[1(S)-(Boc-amino)-2-phenylethyl]-3(R)-[(p-benzyloxyphenyl)methyl]dihydrofuran-2-(3H)-one

Participants

Reaction Steps

In analogy with Example 1h), 1.13 g (3.70 mmol) of 5(S)-[1(S)-(Boc-amino)-2-phenylethyl]dihydrofuran-2-(3H)-one [Example 2b)], dissolved in 4.8 ml of THF and 0.75 ml of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, are deprotonated, at -75° C., with 7.25 ml of a 1M solution of lithium bis(trimethylsilyl)amide in THF, and alkylated (15 min) with 1.2 g (3.7 mmol) of p-benzyloxybenzyl iodide (Example 1d)) in 2 ml of THF. Column chromatography (SiO2, hexane/ethyl acetate, 2:1) affords the pure title compound: TLC Rf (D)=0.30; tRet (I)=28.2 min; FAB-MS (M+H)+ =502.

Provenance & Evidence