- Convenient synthesis of 2,3,9,10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids
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New and convenient synthesis of 2,3,9,10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids through the same intermediates was developed. Acylation of the brominated benzylphenethylamine (13) with α- chloro-α-(methylthio)acetyl chloride, followed by cyclization with stannic chloride, furnished the key intermediates 4-methylthio-3- phenethylisoquinolin-3-ones (14), which were methylated to provide their methyl derivatives (17). Both isoquinolin-3-ones (14, 17) were easily transformed into protoberberine alkaloids (16) and their 13-methyl alkaloids (21) in good yield.
- Hanaoka, Miyoji,Hirasawa, Taeko,Cho, Won Jea,Yasuda, Shingo
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p. 399 - 404
(2007/10/03)
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- The Polonovski-Potier reaction of berbine N-oxides. Synthesis of 8-hydroxymethyl and 8-methylberbines
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The Polonovski-Potier reaction of trans and cis berbines N-oxides was studied. The 8-cyano derivative obtained from trans N-oxides were used to synthesize 8-hydroxymethyl and 8-methyl berbines. This procedure was applied to the stereocontroled synthesis of (8R, 14S)-(-)-8-methylcanadine from (14S)-(-)-canadine. (C) 2000 Elsevier Science Ltd.
- Suau, Rafael,Nájera, Francisco,Rico, Rodrigo
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p. 9713 - 9723
(2007/10/03)
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- UTILIZATION OF PROTOPINE AND RELATED ALKALOIDS.XVIII. SOME REACTIONS OF ANHYDROISODIHYDROCORYCAVIDINE AND ITS N-OXIDE
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Hydroxylation of anhydroisodihydrocorycavidine 4 with osmium tetroxide affords the α-glycol 7 and the 13,14-seco keto aldehyde 8.Treatment of the N-oxide 6 with acetic anhydride/acetic acid gives the 7,8-seco diacetate 10 and the indene acetate 11.The for
- Takahashi, Hiroshi,Iguchi, Mieko,Konda, Yaeko,Onda, Masayuki
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p. 2629 - 2637
(2007/10/02)
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