Glycosylidene Carbenes. Part 3. Synthesis of Spirocyclopropanes

Abstract

Abstract Thermolysis of the glycosylidene‐derived O ‐benzylated diazirine 1 in the presence of N ‐phenylmaleimide ( 2 ), acrylonitrile ( 3 ), dimethyl fumarate ( 4 ), or dimethyl maleate ( 5 ) led in good yields to mixtures of the spirocyclopropanes 6 / 7 , 8 – 11 , 12 / 13 , and 12 / 13 / 16 / 17 . The diastereoselectivity depends upon the alkene. The cycloaddition of 1 to 5 is not diastereospecific, in keeping with previous results. Deprotection of 12 , 13 , 16 , and 17 yielded the tetrols 14 , 15 , 18 , and 19 , respectively.