Total synthesis of the racemates of kaur-16-en-19-OL monogynol and some oxygenated kauranes

ent-Kaurane Diterpenoids from Annona glabra

“…16R-Methoxy-ent-kauran-19-oic acid (5) and 16R-hydro-ent-kauran-17,19-dimethyl ester (6) were obtained for the first time as natural products. The structures of compounds 1-6 were characterized by spectral analysis.…”

“…The acetoxyl group was determined as After the structure elucidation of 16R-methoxy-entkauran-19-oic acid (5) and 16R-hydro-ent-kauran-17,19-dimethyl ester (6) by spectral means, it was determined that these two compounds had been prepared synthetically previously. 5,17 Experimental Section General Experimental Procedures. Melting points were determined using a Yanagimoto micro-melting point apparatus and are uncorrected.…”

Synthesis of Phytohormones, Phytoalexins and Other Biofunctional Molecules of Plant Origin

“…This ester A was prepared from ethyl acrylate, ethanol and methyl acetoacetate via methyl 5-ethoxy-3-oxopentanoate. 42,43 Plant-growth-promoting activity of synthetic (±)-24 was compared with that of natural (−)-24 by Professor M. Katsumi, using dwarf maize d 5 . Tetralone (±)-B was prepared from naphthalene.…”

“…89 We became interested in synthesizing both the enantiomers of pisatin, and accomplished the synthesis of the enantiomers of pterocarpin (43) in 1988 as a model study. 90 Then, in 1989, the enantiomers of pisatin (42) were synthesized, as shown in Figure 2.28. 91 The known isoflavone B 92 was synthesized from sesamol (A) as depicted.…”

“…91 The known isoflavone B 92 was synthesized from sesamol (A) as depicted. Treatment of J with sodium carbonate effected ring closure to give (+)-pisatin (42). When G was treated with TBAF both the camphor-10-sulfonyl and TBS protective groups were removed to give I.…”