Studies on Agarofurans IV. The Synthesis of 4-Substitutioned Agarofurans

A new synthetic route for α-agarofuran(1b) is described. Several agarofuran derivatives were synthesized in similar way. Derivative 1d was also synthesized in a novel way, in which the substitution at C-4 was performed quantitatively. An ideal condition for cyclization of diol 7 to agarofuran (1) was found.