A new synthetic route to β-bromoprop-2-ynyl mixed acetals and bromovinyl bis-allyl mixed acetals, precursors of α-methylene-γ-butyrolactones
作者:J. P. Dulcere、M. N. Mihoubi、J. Rodriguez
DOI:10.1039/c39880000237
日期:——
in methanol of β-bromoallenyl ethers (3a–g) or allyl allenyl ethers (8d–f) affords unsaturated halogeno-compounds (5a–g) or (9d–f) which are converted via homolytic carbocyclization into α-methylene-γ-butyrolactones (7a–g).
ButOK–dimethyl sulfoxide-catalysed selective isomerization of 3-methylene tetrahydrofurans 1 provides a new convenient route to 2,5-dihydrofuran 2 precursors of furan-2(3H)-ones 8 or furans 4 or 9.