Table 2.

Conditions for epoxide ring opening.^[a]

Entry	Conditions	Epoxide [equiv]	Vinyl iodide73[equiv]	Yield [%]
1	thiophene, nBuLi, CuCN, tBuLi, THF, BF3⋅OEt2, −78→−90→−40 °C	61 (1.0)	5.0	72
2	as for entry 1	61 (1.0)	3.5	55
3	as for entry 1	61 (1.0)	2.0	33
4	as for entry 1	74 (1.0)	5.0	60[a]
5	iPrMgCl, CuI,[b] THF, −78 °C	74 (1.0)	1.2	–
6	tBuLi, BF3⋅OEt2, PhMe, −78 °C	74 (1.0)	2.0	11
7	tBuLi, BF3⋅OEt2, PhMe, −78 °C	74 (2.5)	1.0	53[c]

[a] Reagents and conditions: a) allyl bromide, MeCN, PhH, 85 °C, 44 %; b) 71 (5 mol %), Bu₃SnH, THF, RT; c) I₂, CH₂Cl₂, 0 °C, 62 % over 2 steps. [b] Compound could not be purified fully. [c] 25 mol % of CuI was used. [d] Following TBS protection.