Hautriwaic acid

Gambarro et al. [29] reported the isolation and characterization of four clerodane derivatives, two of them new hardwickiic acid, Fig. (7) and hautriwaic acid, Fig. (8) present in Baccharis macraei Hook et Am, a shrub that grows in the coastal area of Central Chile, while Baccharis paniculata D. C. from Northern Chile also yielded two new weo-clerodane diterpenoids [30],... 

These diterpenoids, hautriwaic acid and its derivative 2(3-hydroxyhautriwaic acid which is a novel natural product, were also isolated from the leaf resin of B. sarothroides and B. vaccinoides [31],... 

Feraginidin, in D-60004 Ferugin, in D-60005 Gelomulide A, in G-80008 Hautriwaic acid acetate, in H-70002 Isobretonin A, in D-80526 Lasianthin, L-60017... 

Kolav-3,13(16),14-trien-18-oic acid, 15, 16-epoxy-19-hydroxy-ent- [Hautriwaic acid]... 

Introduction of a hydroxyl function at C-19 has minimal effect on the chemical shift of H-20 (Table 14 and Figure 57 [p. 539]). However, attachment of increasingly bulky ester functions (e.g., angelate) at C-19 appears to result in modest deshielding of H-20. Structure 904 which differs from the related compounds 900, 902, 903, and 1033 (hautriwaic acid) (Figure 57) by the further oxidation of C-19 to an aldehyde is characterized by an H-20 singlet at 60.60. The considerable shielding of this methyl is attributed to the aldehyde (C-19) which is 1,3 diaxially oriented with respect to the C-10 methyl (H-20). 

Arriaga-Giner, F.J., E. Wollenweber, I. Schober, P. Dostal, and S. Braun 2/3-Hautriwaic acid, a clerodane type diterpenoid and other terpenoids from three Baccharis species. Phytochem. 25, 719 (1986). 

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