反应详情

A solution of 5-ethoxycarbonylpenta-2,4-dienyltriphenylphosphorane [prepared by adding N aqueous sodium hydroxide solution (40 ml.) to a stirred solution of 5-ethoxycarbonylpenta-2,4-dienyltriphenylphosphonium bromide (16.4 g.) in water (1000ml.) at 1°-3° C., extracting with chloroform and concentrating the extract to about 250 ml.] was treated at 2° C. under nitrogen with a solution of 3,4-di(2-tetrahydropyranyloxy)-2-[3-(2-tetrahydropyranyloxy)octyl]cyclopentane carbaldehyde (8.5 g.) [prepared as described in (m) above]in chloroform (20 ml.). The solution was allowed to stand at room temperature for 18 hours, the chloroform was removed in vacuo and the residue extracted three times with hot petroleum ether (b.p. 40°-60° C.). The combined petroleum extracts were cooled and filtered to remove precipitated triphenylphosphine oxide. The filtrate was evaporated in vacuo and the residue separated by chromatography on silica gel. Elution with petroleum ether (b.p. 40°-60° C.) gave ethyl 7-{3,4-di(2-tetrahydropyranyloxy)-2-[3 -(2-tetrahydropyranyloxy)octyl]cyclopentyl}-hepta-2,4,6-trienoate (6.4 g.), νmax : 1700 cm-1, 1610 cm-1 (liquid film).

1. extractionextracting with chloroform
2. concentrationconcentrating the
3. extractionextract to about 250 ml
4. addition] was treated at 2° C. under nitrogen with a solution of 3,4-di(2-tetrahydropyranyloxy)-2-[3-(2-tetrahydropyranyloxy)octyl]cyclopentane carbaldehyde (8.5 g.) [
5. customprepared
6. customthe chloroform was removed in vacuo
7. extractionthe residue extracted three times with hot petroleum ether (b.p. 40°-60° C.)
8. temperatureThe combined petroleum extracts were cooled
9. filtrationfiltered
10. customto remove
11. customprecipitated triphenylphosphine oxide
12. customThe filtrate was evaporated in vacuo
13. customthe residue separated by chromatography on silica gel
14. washElution with petroleum ether (b.p. 40°-60° C.)