methyl N-[(2S)-1-hydrazinyl-3,3-dimethyl-1-oxobutan-2-yl]carbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (S)-3-Benzyl-4-((3aS,8aR)-2,2-dimethyl-8,8a-dihydro-3 aH-indeno[1,2-d]oxazol-3-yl)-3-hydroxy-4-oxo-butyraldehyde (21h) (0.082 g, 0.21 mmol) and [N-(methoxycarbony)-L-tert-leucinyl]hydrazine (0.048 g, 0.23 mmol, prepared as reported JMC, 41, 3387, 1998) in dry THF (10 mL) was stirred for 3 h and [the LCMS (ESI+) shows 565 (M+)], then Na(OAc)3BH (0.137 g, 0.64 mmol) was added and stirred overnight. The reaction mixture was quenched with water and evaporated. The residue was dissolved in dichloromethane and washed with water, brine and dried. The crude product was analysed by LCMS (ESI+) which showed 567 (M+) the title compound with a minor quantity of the compound lacking the protection group on the indanol moiety [MS (ESI+): 527 (M+)]. This mixture was alkylated by the next step without purification. was added The reaction mixture was quenched with water evaporated The residue was dissolved in dichloromethane washed with water, brine dried This mixture was alkylated by the next step without purification