Table 1. Temperature and concentration screening in the isocyanoacetate aldol reaction between 8 and 7a  ^a .

Entry	T (°C)	[7a] (M)	Time (h)	Yield b (%)	d.r. c (trans : cis)	e.e. d (%)
1 e	–20	0.3	21 f	45	91 : 9	44
2 e	20	0.3	0.25	59	91 : 9	53
3	20	0.05	0.5	73	91 : 9	69
4	20	0.01	0.5	70	91 : 9	78
5	20	0.0025	17 g	70	90 : 10	80
6	0	0.01	16 f	72	90 : 10	72
7	50	0.01	2	61	88 : 12	65

^aReaction performed on 0.25 mmol of 7a using 1.1 eq. of 8. Configuration of 6a assigned by analogy with previous work.⁹

^bIsolated yield of trans diastereomer after FCC.

^cd.r. determined by ¹H NMR analysis of the crude reaction mixture.

^de.e. of trans diastereomer determined by HPLC on chiral stationary phase.

^e0.50 mmol of 7a.

^fStirred overnight, as TLC control after 3 hours indicated that the reaction was progressing.

^gStirred overnight, as TLC control after 6 hours indicated that the reaction was progressing.