J. Org. Chem. 1980,45, 2151-2155 benzene (15 mL) in the presence of 1 (55.2 mg, 0.06 mmol) and (-)-DIPHOL (118.6 mg, 0.24 mmol) was carried out at 52 OC for 8 days under 500 psi of CO/H2. NMR revealed complete conversion to 20b (CDClJ 6 1.5 ((CH,),C, s), 2.0 (CH2CH2,m), 3.5 (>NCH,, m), 4.1 (>NCHCHO, m), 9.52 (CHO, d, J N 2 Hz). Oxidation by KMn04/Me2CO/MgS04yielded the corresponding acid (720 mg, 6 mmol): NMR (CDCl,) 6 1.4 ((CH3)3C,s), 2.05 (CH2CH2,m), 3.4 (>NCH, m), 4.2 (>NCHCOOH,m), 8.7 (COOH, br 8). Esterification with etheral diazomethane afforded the ester 2Lb as a colorless, viscous oil: NMR (CDC1,) 6 1.3 ((CH,),C, s), 1.9 (CH2CH2,m), 3.65 (CH30C0, s), 4.2 (>NCHCOOCH3, m); yield 379.7 mg (56% from 19b); [ C ~ ] , ~ D+0.19" (0.35% ee). (S)-(-)-N-(tert-Butoxycarbony1)proline((S)-21b). (S)Proline (1.15 g, 10 mmol) and triethylamine (2.1 mL, 15 mmol) were dissolved in dioxane (10 mL). Water (6 mL) and BOC-ON" (t-BuOCOONC(CN)Ph,2.71 g, 11mmol) were added, and after the mixture was stirred at 25 "C for 2.5 h, the homogeneous clear yellow solution was diluted with water (15 mL) and ethyl acetate (20 mL). The aqueous layer was separated, extracted with ethyl acetate (2 X 10 mL), and then acidified with 1 N HCl. The resulting emulsion was extracted with ethyl acetate (3 X 30 mL), dried (MgS04),and concentrated to afford a colorless oil which solidified on standing. (tert-Butoxycarbonyl)prolinewas obtained as a low-melting solid. Esterification with etheral diazomethane followed by column chromatography on silica gel (10% acetone-hexane) gave (S)-21b as a colorless oil which was purified by distillation in a Kugelrohr oven (130 "C, 30 Km), -54.54" (C 10.04, CHC13). Hydroformylation of N-Allylacetamide (29). A mixture of 29 (5.0 mL) and 1 (99.6 mg) in benzene (10 mL) was hydroformylated under 500 psi of CO/H2 (1:l) at 40 "C for 30 h. NMR and TLC analyses showed only a mixture of aldehydes. The crude mixture was fractionated at 0.1 mmHg. Two fractions were collected I, bp 74-78 O C , 1.973 g (mainly starting material); 11, bp 88-94 "C, 2.177 g. This fraction contained no starting material and consisted of 30 and 119a in 5446 ratio, respectively. Oxidation of this mixture with potassium permanganate-acetone yielded an acid which was esterified with diazomethane. The product, methyl 2-methyl-3-acetamidopropionate, was purified on a GLC column [lo f t X 3/8 in. 20% Carbowax 20-M, Chromosorb W (60/80)] a t 225 "C and was obtained as a colorless oil: NMR (CDC13) 6 1.15 (CH3, d, J = 8 Hz), 1.92 (COCH3, s), 2.7 (CH2N
