A. C. Jain, R. Khazanchi, A. Kumar
1979
Citations
0
Influential Citations
5
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
2,4-Dihydroxy-5-methoxyacetophenone on treatment with 3-chloro-3-methyl-1-butyne in the presence of K2CO3, KI, and DMF yielded its 4-(1,1-dimethyl-2-propynyl) ether (2) and the naturally occurring 6-acetyl-5-hydroxy-8-methoxy-2,2-dimethylchromene (3). More of the chromene (3) could be obtained by the thermal cyclisation of the acetophenone (2). Methylation of 3 yielded another natural chromene. 4-Hydroxy-3-methoxyacetophenone, on similar treatment with 3-chloro-3-methyl-1-butyne, gave directly natural 6-acetyl-8-methoxy-2,2-dimethylchromene. 2,3,4-Trihydroxy-5-(3-methyl-2-butenyl)acetophenone, on cyclodehydrogenation followed by methylation with 1 mol of dimethyl sulfate, yielded natural ripariochromene-A. Further methylation provided methylripariochromene-A.