Table 1.

Identification of optimal reagents for constructing l-allo-End

Entry	Conditions	Yield
1a	10% Pd(OAc)2, 2 equiv. CuCl2, 2 equiv. NaHCO3, MeCN, RT, 1 h	5%
2a	3 equiv. tBuOCl, DCM, RT, 2 h	<5%
3a	2 equiv. NIS, 4 equiv. NaHCO3, MeCN, 0 °C, 0.5 h	52% (dr 5:1)
4a	3 equiv. I2, 4 equiv. NaHCO3, MeCN, RT, 1 h	56%
5a	3 equiv. I2, 4 equiv. NaHCO3, MeCN, 0 °C, 1 h	65% (dr 5:1)
6b	3 equiv. I2, 4 equiv. NaHCO3, THF, 0 °C, 1 h	71% (dr > 15:1)
7c	3 equiv. I2, 4 equiv. NaHCO3, MeCN, 0 °C, 1 h	61% (dr > 15:1)

^aR₁ = Phth, R₂ = Boc

^bR₁ = Fmoc, R₂ = Cbz

^cR₁ = Boc, R₂ = Cbz