Carlosic acid

Total synthesis and absolute configuration of (S)-carlosic acid, J.L. Bloomer and F.E. Kappler, J. Chem. Soc., Perkin Trans. 1, 1976, 1485. 

The biosynthesis of the fungal tetronic acid carolic acid (76 a) in Penicillium charlesii is markedly different from that of patulin, multicolic acid and penicillic acid. Carbon-14 work has demonstrated that the carbon sub-unit C-3, C-4, C-9 in the acid is derived from a C-4-dicarboxylic acid such as succinate, whereas the remaining six carbons (C-1, C-2, C-5, C-6, C-7, C-8) are derived from two malonate units (C-5, C-6, C-7, C-8) and just one acetate unit (C-1, C-2) (Scheme 19) (775). It is proposed then that the biosynthesis of carolic acid proceeds from a C4-dicarboxylic acid first to either y-carboxymethyltetronic acid (196) or to carlosic acid (77 b) hydroxylation of carlosic acid then gives rise to carlic acid (77 a) which on decarboxylation produces carolic acid 176). 

Syntheses, published in 1976, of naturally occurring tetronic acids include those of (S )-carlosic acid (75) and the related (/ )-carolic acid and of fungal pigments based on the pulvinone e.g. 76) and pulvinic acid e.g. 77) structures. 

Car-3-ene, A35 Car-4-ene, T5 /raw5-car-4-ene-3- ol, T6 Caracurine VII, K12 fraw5-caran-2-one, T6 Caranes, T6 Caranine, K6 Carbodiimides, X3 Carbomycin, Y25 Carbonates, A14-15 Carbonyls, X9, X2, Zl / -carboxybutyramide, A34 Cardenolides, T49 Cardiolipin, A15 Carlosic acid, A12 Carminomycin, Y28 Carnitine, A2 Carnosine, A20 Carnosol, T33 Carolic acid, A12 ... 

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