1-[1-（Benzyloxy）-3-methylnaphthalen-4-yloxy]propan-2-one （la） took place a cyclization, debenzylation and oxidation to form 9-substitued benzo[de]chromene-7,8-dione （2a） and 5-benzyl-9-substitued benzo[de]chromene-7,8-dione （3a）. The mechanisms for these reactions were discussed.
Shi Liang HUANGYi LUOZhi Shu HUANGXian Zhang BUPei Qing LIULin MAYue Ming LIAlbert S. C. CHANLian Quan GU
A new bisbenzofuran analogue Ⅶ was achieved unexpectedly in one step procedure from 1-（4-methoxyphenoxy）acetone Ⅰ by using Amberlyst 15 resin as catalyst in excellent yield. The structure was elucidated by spectroscopy analysis including ^1H-NMR, ^13C-NMR, DEPT, ESI-MS, element analysis.
Yu Dong SHENHai Qiang WULin Kun ANZhi Shu HUANGXian Zhang BULian Quan GU
A new sesquiterpenoid lactone, 3,6,9-trimethyl-pyrano[2,3,4-de]chromen-2-one (1) and a novel sesquiterpenoid quinone, 6-[2-(5-acetyl-2,7-dimethyl-8-oxo-bicyclo[4.2.0]octa-1,3,5- trien-7-yl)-2-oxo-ethyl]-3,9-dimethylnaphtho[1,8-bc]pyran-7,8-dione (2) together with a known perezone (3) were isolated from the roots of Helicteres angustifolia. The structures were elucidated as mainly on the basis of 1D and 2D NMR spectroscopic data.
From the roots of Helicteres angustifolia, collected from Anhui province, two triterpenoids of oleanolic acid type were obtained and were identified as new compounds, methyl 3β-hydroxyolean-12-en-27-benzoyloxy-28-oate(1) and 3β-O-(p-hydroxy-(E)-cinnamoyl)-12 oleanen-28-oic acid(2). The variety of spectroscopic methods such as IR, HRMS, EIMS, H-H COSY, H-C COSY NMR have been applied in the structural elucidation of these two compounds.
