Table 1.

Selected examples from the optimization.

Entry	Initiator	mol %	Time	Yield [%][a]
1	tBuOLi	10	1 h	91
2	Me3SiOLi	10	1 h	>95
3	Me3SiONa	10	<5 min	98 (70)[b]
4	Me3SiOK	10	<5 min	90
5	Me3SiONa	5	<5 min	>95
6	Me3SiONa	1	20 h	6
7	Me3SiOK	1	20 h	58
8	CsF	10	20 h	60
9	TMAF	10	20 h	trace

[a] Determined by calibrated GLC analysis with tetracosane as an internal standard. [b] Yield of isolated product on a 0.40 mmol scale after flash chromatography on silica gel in parentheses. TMAF=tetramethylammonium fluoride.