. 2008 Jun 24;130(29):9182–9183. doi: 10.1021/ja800402g

Table 1. Reaction of 5a with 1 or 2 Activated in situ^a.

entry	borane source	activator	time (h)	conversion^b (%)	9a:10a^b
1	1	I₂	10	40	4.3:1
2	1	I₂	19	>90	4.7:1
3	2	I₂	5	>90	7:1^c
4	2	I₂	5	>90	18:1^d
5	1	TfOH	5	>90	>20:1

A 0.1 M solution of 5 and 2 equiv of 1 or 2 at −78 °C in CH₂Cl₂ was treated with 2 equiv of activator, warmed to −20 °C, stirred (time), and quenched with NaOOH/MeOH·H₂O.

NMR assay.

Activated at −20 °C and warmed to −10 °C.

Warmed to −10 °C.

Table 1. Reaction of 5a with 1 or 2 Activated in situa.

Table 1. Reaction of 5a with 1 or 2 Activated in situ^a.