(3,3)Sigmatropic Ring Expansion of Cyclic Thionocarbonates. IV. Relationship between Ring Size of Cyclic Thionocarbonates and Geometry of Created Double Bond in Medium- and Large-Membered Thiolcarbonates.
(3,3)Sigmatropic Ring Expansion of Cyclic Thionocarbonates. IV. Relationship between Ring Size of Cyclic Thionocarbonates and Geometry of Created Double Bond in Medium- and Large-Membered Thiolcarbonates.
[3,3]sigmatropic ring expansion of cyclic thionocarbonates. 13.1 synthesis of medium-membered heterocyclic allenes and synthetic application to antifungal constitutent of Sapium japonicum
thionocarbonates (2i-k) afforded a new type of strained 8-membered heterocyclic allenes (3i-k) in high yields. The MNDO optimized structure of 3i indicated the allenyl moiety was bent and strained. The reactivity of 8-membered cyclic allenes was also examined. Further, using this methodology with a novel application of a SmI2-HMPA reduction of the resulting heterocyclic allene (3n), an antifungal constituent