Table 2.

Preparation of Alkoxyallenes from Propargylic Ethers^a,^b

entry	substrate	R1	R2a	conditionsb	product (R3)	yield (%)
1	18a	Ph	Et	A, B, C, D, E, F	c	–
2	18a	Ph	Et	G	19a (SiMe3)	40
3	18a	Ph	Et	H	19b (SnBu3)	95
4	18b	Ph	PMB	H	19c (SnBu3)	94
5	18c	Ph	OMB	I, J, K, L, M	c	–
6	18d	H	PMB	N	20 (H)	~90

^aPMB=p-methoxybenzyl; OMB=o-methoxybenzyl

^bConditions: A) KOt-Bu, MeOH, THF. B) MeLi, THF then MeOH. C) MeLi, THF then ZnCl₂ then NH₄Cl. D) t-BuLi, THF then imidazole. E) t-BuLi, THF then ZnCl₂ then NH₄Cl. F) Triton B^®, DMSO, 50°C. G) 1.3 equiv. t-BuLi then TMSCI, THF, −30°C. H) t-BuLi, Et₂O, −40°C then Bu₃SnCl. I) t-BuLi, THF then MeOH. J) t-BuLi, TMEDA, THF then MeOH. K) t-BuLi, TMEDA, THF then t-BuOH. L) t-BuLi, TMEDA, THF then 2,6-di-t-butylphenol. M) t-BuLi, TMEDA, THF then imidazole. N) Triton B^® (40% w/w MeOH), DMSO, 50°C

^cPropargylic ether was isolated unchanged.