(1) Synthesis of 2-tetralones by titanium tetrachloride-Promoted cyclization of 4-aryl-2-hydroxybutanal dimethyl acetals.(2) Synthesis of benzocoumarins from 2-tetralones.

• Main Authors: Chia- fen Wu, 吳佳芬
• Other Authors: Hon. Y.-S.
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/77040416790529510687

碩士 === 國立中正大學 === 化學所 === 98 === (1) 2-tetralone is useful in synthetic chemistry, it could be used in many kinds of applications, such as precursors of several natural products and their derivatives, starting materials for synthetic compounds with biological activities and other useful properties. So far, it is not safe and efficient Methodologies from the monocyclic aromatic precursor such as the potential carcinogenicity hazards associated with diazo compound and low boling point ethylene as reagent to preapare 2-tetralone. A general and efficient methodology to prepare 2-tetralone derivatives has been developed. We have prepared ?-dimethyl acetal Weinreb amide and then use it to synthesize 2-tetralones via titanium tetrachloride- promoted cyclization of 4-aryl-2- hydroxybutanal dimethyl acetals . (2) The coumarin subunit is used in many kinds of synthetic chemistry, it is found in many natural products displaying diverse biological activities. It’s exist in antifungals, anticoagulants, compounds active against psoraris and carcinogens. So far, the 5,6-benzocoumarin has been synthesized by bicyclic aromatic 2-naphthol as starting material. We have prepared 2-tetralone and further converted it to 5,6-benzocoumarin by three steps. The first step is added methyl ester to form enol from ketone in conjugated system, then in strong acid condition, the hydroxy reacted with propiolic acid to form tricyclic benzocoumarin skeleton then aromatize from alkane by oxidant-DDQ to form 5,6-benzocoumarin.