A mild conversion of phenylpropropnoid into rare phenylbutanoids: (E)-4-(2,4,5-trimethoxyphenyl)but-1,3-diene and (E)-4-(2,4,5-trimethozypheny)but-1-ene occuring in Zingiber cassumunar.
(E)-4-(2',4',5'-trimethoxyphenyl)but-1,3-diene (4) and (E)-4-(2',4',5'-trimethoxyphenyl)but-1-ene (6), bioactive phenylbutanoids of Zingiber cassumunar, were synthesized exclusively with trans geometry. Treatment of methylmagnesium iodide with (E)-2',4',5'-trimethoxycinnamaldehyde (2), an oxidized product of abundantly available toxic (Z)-phenylpropanoid (1) of Acorus calamus, gave (E)-4-(2',4',5'-trimethoxyphenyl)but-3-en-2-ol (3) which upon dehydration with copper sulphate/silica gel under microwave irradiation for 3 min afforded 4 in 58% yield. Further, catalytic hydrogenation of 4 with 10% Pd/C afforded 4-(2',4',5'-trimethoxyphenyl)butane (5) which upon dehydrogenation with DDQ/SiO2 afforded hypolipidemic 6 in 54% yield.
Sinha
Arun K
AK
Natural Plant Products division, Institute of Himalayan Bioresource Technology, Palampur (H.P.)-176061, India. aksinha8@rediffmail.com
Sharma
Anuj
A
Joshi
Bhupendra P
BP
Singh
Narendra P
NP
D002073:Butanes / Q000138:chemical synthesis* / Q000737:chemistry*; D010666:Phenylpropionates / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D030521:Zingiberaceae / Q000737:chemistry*
C508393:(E)-4-(2,4,5-trimethoxyphenyl)but-1,3-diene; C508392:(E)-4-(2,4,5-trimethozypheny)but-1-ene; D002073:Butanes; D010666:Phenylpropionates; D010936:Plant Extracts