2001 rearrangements

rearrangementsO 0140

15 - 052ortho-[2,2]-Wittig Rearrangement of Benzyl Propargyl Ethers: Strik-ing Preference over the Competing [1,2]-Wittig Shift. — Treatmentof benzyl silylpropargyl ether (I) with BuLi in THF solutions affords therarely precedent ortho-[2,3]-Wittig rearrangement product (II) in remarkablylarge preference to competing [1,2]- and [1,4]-shift products (III) and (IV),respectively. Factors governing the peri-selectivity in this type of carbanionrearrangement are studied systematically. — (TOMOOKA, KATSUHIKO;HARADA, MANABU; HANJI, TAKAYUKI; NAKAI, TAKESHI; Chem. Lett.(2000) 12, 1394-1395; Dep. Chem. Technol., Tokyo Inst. Technol., Meguro,Tokyo 152, Japan; EN)

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