Asymmetric [2,3] Wittig rearrangement of crotyl furfuryl ethers

Asymmetric Wittig rearrangement of crotyl furfuryl ethers was investigated in diastereo- and enantioselective manners. Both (2S,3Z)- and (2S,3E)-3-pen ten-2-yl furfuryl ethers 3 and 9 rearranged with complete chirality transfe r to give the syn- and anti-isomers 4 and 10, respectively. Enantioselectiv e Wittig rearrangement of both (Z)-and (E)-crotyl furfuryl ethers 15 and 17 using butyllithium and (-)-sparteine was examined to afford (1S,2R)-1-(2-f uryl)-2-methyl-3-buten-ol 16 in up to 43% ee. (C) 2001 Elsevier Science Ltd . All rights reserved.