Table 1.

Electrophile scope with linchpin 15.^[a]

Entry	E+	Product	Yield
1	Mel	17	78%
2		18	75%
3	a)X=Br b)X=1	19	a) 59% b) 74%
4	a)X=Br b)X=1	20	a) 52% b) 67%
5	a)X=Br b)X=1	21	a) 55% b) 69%
6	Et3SiCl	22	71%
7	(R)-epichiorohydrin	(R)-23	60%

^[a]Reaction conditions: i) 15, THF, –78° C, then slow addition of nBuLi; ii) electrophile, HMPA, THF, –78° C to –30° C; iii) sat. aq. NH₄Cl.