CarbaMic acid, N-[(1S,3R)-1,3-bis(hydroxyMethyl)-5-hexen-1-yl]-, 1,1-diMethylethyl ester synthesis

Yield:942144-12-9 85%

Reaction Conditions:

Stage #1: (2S,4R)-1-tert-butyl 4-allyl-2-ethoxycarbonyl-5-oxopyrrolidine-1-carboxylatewith sodium tetrahydridoborate in methanol;lithium hydroxide monohydrate at 20; for 1 h;
Stage #2: with lithium hydroxide monohydrate;ammonia hydrochloride in methanol;

Steps:

1.2

To a solution of (2S,4/?)-l-tert-butyl 2-ethyl 4-allyl-5-oxopyrrolidine-l,2- dicarboxylate (30 g, 0.1 mol) in MeOH/H₂O (700/70 mL) was added NaBH₄ (25 g, 0.66 mol), the result mixture was stirred 1 hr at rt and quenched with sat. aq. NH₄Cl (300 mL). The organic solvent was removed under vacuum and extracted with EtOAc (3*250 mL). The combined organic phases were washed with brine (250 mL) and dried over anhydrous Na₂SO₄, filtered and evaporated to afford crude tert - butyl (2S,4/?)-l-hydroxy-4-(hydroxymethyl)hept-6-en-2-ylcarbamate (22 g, 85%). It was used in the next step without further purification.

References:

WO2008/156817,2008,A2 Location in patent:Page/Page column 88-89