59805-79-7Relevant articles and documents
New aspects in the synthesis of mono- and dialkylfurans
Bock, Inge,Bornowski, Hans,Ranft, Andreas,Theis, Heinz
, p. 1199 - 1210 (1990)
3-substituted furan systems can be obtained by alkylation of 3-lithium furans with various electrophiles in the presence of hexamethylphosphoric acid triamide in good yields. The 2- or 5-position of 3-methyl furan is blocked with high regio selectivity by silylation. After metalation and alkylation of the remaining free α-position and subsequent desilylation the 2,3- and 2,4-disubstituted furans are obtained. These methods are used to synthesize the naturally occuring compounds ursinanolide (2) and longifolin (4).