4- alkyl-4-hydroxy cyclopentenone

Group IV substituted, 1, 609-614 Cyclopentenone, 2-alkyl-4-hydroxy-synthesis, 1, 424... 

Microbial hydroxylation reactions of 2-alkyl-substituted 3-methyl-2-cyclopentenones have also been reported. For example, Aspergillus niger ATCC 9142 and Streptomyces aureofaciens were the most suitable strains for introduction of a hydroxy group in the 4-position of cinerone (23), yielding 60% and 42%, respectively, of cinerolone (24). Analyzed byproducts were 25 and 26369 370. 

Kuhn, C, Florent, J-C, A carbohydrate approach to 4-hydroxy-2-cyclopentenone moiety of antitumor prostanoid punaglandin IV via alkylation of ester uronate, Tetrahedron Lett., 39, 4247-4250, 1998. 

The f-butylthiolester 134 provides the silyl enol ether 135 as the acetate enolate equivalent and adds to cyclopentenone with fluoride catalysis to give the silyl enol ether 136. Release of the naked enolate and alkylation with the alkyne 137 gives 138 which has the correct anti stereochemistry and can simply be transformed into the hydroxy acid.18 The final cyclisation demands special methods we shall meet in chapter 43. 

Arnap J., Enzell C., Peterson K. and Petterson T. (1986) A chemical and MS study of tobacco smoke alkyl 2-hydroxy-2-cyclopentenones. Acta Chem. Scand. B40, 839-54. 

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