Scandium-catalyzed propargylation of 1,3-diketones with propargyl alcohols bearing sulfur or selenium functional groups: useful transformation to furans and pyrans.
Propargylations of 1,3-diketones using 3-sulfanyl and 3-selanylpropargyl alcohols 1 in MeNO(2)-H(2)O gave alkynyl ketones 2a-m, 2o-v and 6,7-dihydro-5H-cyclohexa[b]pyran-5-ones 3k-n. With some bases, the useful propargylated 1,3-diketones underwent intramolecular cyclization to give 6,7-dihydro-5H-benzofuran-4-ones 4a-i or 4,5,6,7-tetrahydrobenzofurans 5p, 6p-v.
Ohta
Katsuki
K
Department of Chemistry, Faculty of Education, Gifu University, Gifu 501-1193, Japan.
Kobayashi
Taira
T
Tanabe
Genzoh
G
Muraoka
Osamu
O
Yoshimatsu
Mitsuhiro
M
D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D005663:Furans / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry*; D012538:Scandium / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry; D013457:Sulfur Compounds / Q000737:chemistry
D000480:Alkynes; D005663:Furans; D007659:Ketones; D020005:Propanols; D011714:Pyrans; D018036:Selenium Compounds; D013457:Sulfur Compounds; C028255:propargyl alcohol; D012538:Scandium