Structure and Synthesis of Novel C12 Terpenoids from Quince Fruit (Cydonia oblonga MILL.)

Article abstract of DOI:10.1002/hlca.19910740119

The structure and synthesis of novel irregular C12 terpenoids isolated from quince fruit (Cydonia oblonga MILL.) are described: quince oxepine (= (E)-2,3,6,7-tetrahydro-4-methyl-2-(3-methylbuta-1,3-dienyl)oxepine; 3) and the quince oxepanes as a 1:1 mixture of cis- and trans-isomers (= cis- and trans-(E)-4-methyl-2-(3-methylbuta-1,3-dienyl)oxepane; 4 and 5, resp.).The absolute configuration of the natural compounds have not been determined due to the minute amounts available, but both relative and absolute configuration of synthetic 4 and 5 were established by chemical correlations with (R)-pulegone.