title: Synthesis of 18,19-dihydroxycorticosterone.
abstract: A four-step synthesis of 18,19-dihydroxycorticosterone 5c, starting with 19,21-dihydroxy-3,20-dioxopregn-5-ene-18,11 beta-lactone-di-(ethylene ketal) 2, is presented. Reduction of 2 with sodium aluminum bis-(methoxyethoxy)hydride gave 11 beta,18,19,21-tetrahydroxy-pregn-5-ene-3,20-dione-di-(ethylene ketal) 3a. Acetylation furnished the corresponding 18,19,21-triacetate 3b, which on treatment with a mixture of perchloric and acetic acids gave 18,19-dihydroxycorticosterone 18,19,21-triacetate 4b. Mild saponification yielded the title compound which, on the basis of ir and nmr spectra, exists as one C-20 isomer of the hemiacetal structure 5c. Periodate oxidation of 5c gave the expected 11 beta, 19-dihydroxy-3-oxoandrost-4-ene-17 beta, 18-carbolactone 6b.
mesh_terms: D015069:18-Hydroxycorticosterone / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D015070:18-Hydroxydesoxycorticosterone / Q000031:analogs & derivatives / Q000378:metabolism; D000107:Acetylation; D003345:Corticosterone / Q000031:analogs & derivatives*; D007536:Isomerism; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship
chemical_list: D015070:18-Hydroxydesoxycorticosterone; C051957:18,19-dihydroxycorticosterone; D015069:18-Hydroxycorticosterone; C036775:18,19-dihydroxydeoxycorticosterone; D003345:Corticosterone