A synthesis of 11-homo-aldosterone

Selenol Protecting Groups in Organic Chemistry: Special Emphasis on Selenocysteine Se-Protection in Solid Phase Peptide Synthesis

“…Installation of the Se-phenyl functionalization proceeds by two (now somewhat familiar) general synthetic pathways, all involving delivery of the phenylselenyl moiety as a singular module. The most commonly utilized protocol is attack of an enolate nucleophile on a selenyl electrophile, either in the form of diphenyldiselenide [ 45 ] or phenylselenyl chloride [ 46 , 47 ]. Alternatively, The phenylselenyl component can act as nucleophile, delivered to various types of electrophiles such as allylic halides [ 48 ], Michael acceptors [ 49 ], and epoxides [ 50 ] ( Figure 10 ).…”

“…Alternatively, The phenylselenyl component can act as nucleophile, delivered to various types of electrophiles such as allylic halides [ 48 ], Michael acceptors [ 49 ], and epoxides [ 50 ] ( Figure 10 ). Once installed and functionalized, oxidative elimination can be carried out on the functionalized selenium using a wide variety of oxidants, including hydrogen peroxide [ 46 ], ozone [ 47 ], and sodium periodate [ 50 ]. A representative example with high synthetic merit is van der Donk's synthesis of dehydroalanine-containing peptides via oxidative elimination of phenyl-conjugated selenocysteine residues [ 51 ].…”

Steroids: reactions and partial syntheses

“…95 Syntheses of 1 7a-methoxymethylprogesteronel 96 and the four diastereomeric 3,6-diamino-5a-pregnanes have been reported. 97 The 17-oxime (1 94) was converted into the D-homoaromatic compound (195) in which C-17a is the original C-18. Such incorporation, which occurs in the biosynthesis of Nicandra steroids, was achieved' 98 via the Beckmann fragmentation product (196), which was hydrolysed to the acid (197) and which cyclized to the enone (198).…”

Απομόνωση και φαρμακολογική αξιολόγηση βιοδραστικών μεταβολιτών από θαλάσσια φανερόγαμα (Cymodocea nodosa), χλωροφύκη (Acetabularia acetabulum ) και μικροφύκη (Odontella aurita, Galdieria sulphuraria, Chaetoceros sp.)

“…πρωτονίων στους δακτυλίους του στεροειδούς. Αντιπαράθεση των αναφερθέντων φασματοσκοπικών δεδομένων με αυτών της βιβλιογραφίας έδειξε ικανοποιητική ταύτιση του μεταβολίτη 8 με το γνωστό μεταβολίτη 1,4-χολεσταδιεν-3-όνη (Minami et al, 1986;Miyano et al, 1982 Σύγκριση των φασματοσκοπικών αυτών δεδομένων με αυτών της βιβλιογραφίας (Matsumoto et al, 1983;Horibe et al, 1989) Η βιβλιογραφική έρευνα που ακολούθησε έδειξε ότι ο μεταβολίτης 10 ταυτίζεται με το γνωστό βρωμιωμένο σεσκιτερπένιο ισολαουρενισόλη (isolaurenisol) (Εικ. 59) που έχει απομονωθεί στο παρελθόν από είδη του ροδοφύκους Laurencia (König et al, 1994; (Webster και Stone, 1994).…”