Table 1. The enantioselectivity and stereochemical correlation between the hydrogen isotope chirality of achiral amino acids, i.e., glycine 1 and α-methylalanine 2, and absolute configuration of the subsequent pyrimidyl alkanol 4 .

		Pyrimidyl alkanol 4
Entry	Amino acida (% ee)	Yieldb (%)	eec (%)	Config.
Series I (glycine-α-d1)d
1	(S)-1 (93)	94	96	S
2	(S)-1 (93)	98	95	S
3	(S)-1 (94)	94	94	S
4	(S)-1 (94)	95	93	S
5	(R)-1 (96)	94	93	R
6	(R)-1 (96)	94	91	R
7	(R)-1 (92)	90	91	R
8	(R)-1 (92)	93	92	R
Series II (α-methyl-d3-alanine 2)e
9f	(R)-2 (81)	95	99	S
10f	(R)-2 (81)	97	98	S
11	(R)-2 (81)	94	96	S
12	(R)-2 (81)	92	97	S
13f	(S)-2 (69)	99	98	R
14f	(S)-2 (69)	93	99	R
15	(S)-2 (69)	84	97	R
16	(S)-2 (69)	93	96	R

^aThe ee of 1 and 2 were determined from the ¹H NMR spectrum of the camphanyl amide of 1 and the MTPA amide of 2.

^bIsolated yield.

^cThe ee was determined using HPLC employing a chiral stationary phase.

^dThe molar ratio was 1/3/i-Pr₂Zn = 0.05/1.05/2.2. The aldehyde 3 and i-Pr₂Zn were added in three separate portions. Experimental details are as follows (entry 1): i-Pr₂Zn (0.15 mL of 1 M methylcyclohexane (MCH) solution, 0.15 mmol) was added to (S)-1 (3.8 mg, 0.05 mmol) and the mixture was stirred for 12 h at room temperature. After the addition of i-Pr₂Zn (0.5 mL of 1 M MCH solution, 0.5 mmol,) at 0 °C, a MCH (2.0 mL) solution of 3 (9.4 mg, 0.05 mmol) was added over a period of 1 h and the mixture was stirred for 6 h at 0 °C. After toluene (3.2 mL) and i-Pr₂Zn (0.4 mL of 1 M toluene solution, 0.4 mmol) were added, the reaction mixture was stirred for 10 min. Then, a toluene (1.5 mL) solution of 3 (37.6 mg, 0.2 mmol) was added over a period of 1 h at 0 °C, and the mixture was stirred for 2 h. Moreover, after toluene (14.4 mL) and i-Pr₂Zn (1.6 mL of 1 M toluene solution) were added and the mixture was stirred for 10 min, a toluene (4.0 mL) solution of 3 (150.6 mg, 0.8 mmol) was added over a period of 1 h. After stirring for 1 h, the reaction was quenched with 1 M aqueous hydrochloric acid (5 mL) at 0 °C. After neutralization with saturated aqueous sodium hydrogen carbonate (15 mL), the mixture was filtered through Celite, and the filtrate was extracted with ethyl acetate. The combined organic fractions were dried over anhydrous sodium sulfate and evaporated in vacuo. Purification of the residue using silica gel thin layer chromatography (hexane–ethyl acetate = 2/1, v/v) gave (S)-4 (229 mg, 0.9849 mmol, 96% ee) in 94% yield.

^eThe molar ratio was 2/3/i-Pr₂Zn = 0.075/0.625/1.35. The aldehyde 3 and i-Pr₂Zn were added in four separate portions.

^fEach pair of reactions (9/13 and 10/14) was performed using the same apparatus to exclude any effect other than that of isotopically chiral amino acid 2.