6-Protoilludene

A modern variant is the intramolecular magnesium-ene reaction, e.g. the reaction of the alkene-allylic-Grignard compound 9 to give the five-membered ring product 10. This reaction proceeds regio- and stereoselectively, and is a key step in a synthesis of the sesquiterpenoid 6-protoilludene ... 

In 1976, Nozoe, et al. isolated and identified hirsutene (651) from an extract of the mycelium of Coriolus consors. Matsumoto has described the transformation of the protoilludene 652 and humulene (653) into 651 and other compounds... 

Further indirect support for this proposal has been provided by the recent demonstration that A -protoilludene (214) and compounds (215)— 220), belonging to some of the structural classes shown in Scheme 24, co-occur in the fungus Fomi-topsis insularia. Blennin A (221) and blennin B (222) have been identified as new metabolites of the inedible mushroom Lactarius blennius and a revised structure has been proposed for the co-metabolite, blennin C (223). An attempt to synthesize velleral (224) has provided a compound (225) which would seem to be... 

Pentalenene synthase fi-om Streptomyces sp. was cloned and overexpressed in Escherichia coli getting pentalenene, a known sesquiterpene site-directed mutants yielded other known sesquiterpenes, A -protoilludene and germacrene A (Seemann 1999). 

Dehydration.1 Usual methods for dehydration of the hydroxy aldehyde 2 are unsatisfactory, but 1 effects the desired conversion to 3 in 90% yield. The product is a precursor to 6-protoilludene (4), a natural product considered to be an intermediate in the biosynthesis of humulenes. 

Highly diaslereocontrolled formation of a cM-l,2-disubstituted five-membered ring was again observed in the key step (105) (106) of the synthesis of ( )-6-protoilludene (111) (Scheme 24). Cop-... 

Hanssen, H.-P., E. Sprecher, and W.-R. Abraham 6-Protoilludene, the Major Volatile Metabolite from Ceratocystis piceaea Liquid Cultures. Phytochem. 25, 1979 (1986). 

---