Photochemical Reactions of Prop-2-enyl and Prop-2-ynyl Substituted 4-Aminomethyl- and 4-Oxymethyl-2(5H)-furanones
作者:Thorsten Bach、Diego A. Fort、Thomas J. Woltering、André M. Alker
DOI:10.3987/com-13-s(s)67
日期:——
Compounds with a heterocyclic 9-oxatricyclo[5.3.0.0(1,5)]decan-8-one skeleton were synthesized by intramolecular [2+2] photocycloaddition reactions of the title compounds (lambda = 254 nm, Et2O or MeCN as the solvent). Starting from various substituted 4-(prop-2-enylaminomethyl)-2(5H)-furanones, products 5, 9, 18, 21, 23, 24 were obtained, which bear a nitrogen atom in position 3 of this skeleton within a pyrrolidine ring. The Boc or Cbz groups represent suitable nitrogen protecting groups, which were compatible with the irradiation conditions and which can be easily cleaved. In an analogous fashion an oxygen (product 22) and carbon substituent (product 25) could be implemented at position 3 of the product if the starting material was appropriately chosen. The prop-2-ynyl substituted substrates did not produce a [2+2] photocycloaddition product but rather underwent a cyclization to spiro products 11 and 13.
An Intramolecular [2 + 2] Photocycloaddition Approach to Conformationally Restricted Bis-Pyrrolidines
作者:Diego A. Fort、Thomas J. Woltering、André M. Alker、Thorsten Bach
DOI:10.1021/jo501302f
日期:2014.8.1
With N-Boc-protected 4-(allylaminomethyl)-2-(5H)furanones as starting materials, a photochemical approach is presented to give 3,9-diazatricyclo[5.3.0.0(1,5)]decanes as conformationally restricted bis-pyrrolidines. The products are orthogonally protected at the two nitrogen atoms and exhibit, depending on the substitution pattern at positions C5, C6, and C7, latent C-2 symmetry. When the furanones had a phenyl group at the 3-position (X-3), alternative photochemical pathways were observed.
Chlorination of 2-fluoropropene. 3-Chloro-2-fluoropropene and some of its derivatives
作者:Leonard Oro Moore、Joseph P. Henry、Jared W. Clark