Table 1:

Reaction between 1 and Boc-D-alanine.

Entry	Coupling Reagent	Boc-D-Alanine	Additive	Conditions	Solvent	Yield (%)
1a	DCC, 1.2 eq	1.0 eq	None	24 hr, rtg	CH2Cl2	59
2b	DCC, 1.2 eq	1.0 eq	None	48 hr, rtg	CH2Cl2	60
3b	DCC, 1.2 eq	1.0 eq	None	24 hrg, 40 ºC	CH2Cl2	55
4 b	DCC, 2.0 eq	2.0 eq	None	24 hr, rtg	CH2Cl2	62
5b,c	DCC, 1.2 eq	1.0 eq	None	24 hr, rtg	CH2Cl2	57
6b,d	DCC, 1.2 eq	1.0 eq	None	24 hr, rtg	CH2Cl2	10
7b	DCC, 1.2 eq	1.0 eq	DMAP, 0.1 eq	24 hr, rtg	CH2Cl2	53
8b	DCC, 1.2 eq	1.0 eq	DMAP, 1.0 eq	24 hr, rtg	CH2Cl2	50
9b	DCC, 1.2 eq	1.0 eq	None	24 hr, rtg	CH3CN	9
10e	EDCI, 1.2 eq	1.0 eq	TEA, 1.2 eq	24 hr, rtg	CH2Cl2	10
11e	EDCI, 1.2 eq	1.0 eq	TEA, 1.2 eq DMAP, 1.2 eq	24 hr, rtg	CH2Cl2	39
12f	Methyl chloroformate	1.5 eq	NMM, 3 eq	24 hr, rtg	THF	50
13f	Ethyl chloroformate	1.5 eq	NMM, 3 eq	24 hr, rtg	THF	25
14f	Isobutyl chloroformate	1.5 eq	NMM, 3 eq	24 hr, rtg	THF	22

^a204 mmol scale

^b68 mmol scal

^cAddition of Boc-D-alanine to a solution of 1 and DCC

^dAddition of 1 to a solution of DCC and Boc-D-alanine

^e22.1 mmol scale

^f21.6 mmol scale

^grt = room temperature