NATURAL PRODUCTS WITH FUSED OXIRANE OR THIIRANE RINGS

7 NATURAL PRODUCTS WITH FUSED OXIRANE OR THIIRANE RINGS 

A few natural products with oxirane rings fused to five-membered rings are known. These include the antibiotic methylenomycin-A (82) (79H(13)353, 79JOC4210,80JA3904, 81CC714) and the truly remarkable fungal metabolite trichoviridine (83), which appears to be the first example of an isocyanide epoxide (76CPB832). 

Few naturally occurring fused-ring thiiranes are known. Recently, however, humulene-1,2- and -4,5-episulfides (84) and (85), and caryophyllene-4,5-episulfide (86) were isolated from hops which had been heavily dressed with sulfur during the growing period, to control mildew (80JCS(P1)311). 

Fused-ring Oxiranes, Oxirenes, Thiiranes and Thiirenes 

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