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Titolo:
NEW SYNTHESIS OF 28-HOMOBRASSINOLIDE FROM STIGMASTEROL
Autore:
HAZRA BG; KUMAR TP; JOSHI PL;
Indirizzi:
NATL CHEM LAB,ORGAN CHEM SYNTH DIV PUNE 411008 MAHARASHTRA INDIA
Titolo Testata:
Liebigs Annalen
fascicolo: 5, , anno: 1997,
pagine: 1029 - 1034
SICI:
0947-3440(1997):5<1029:NSO2FS>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
GROWTH-PROMOTING STEROIDS; STEREOSELECTIVE SYNTHESIS; BRASSINOLIDE; BRASSINOSTEROIDS; ANALOGS; DOLICHOSTERONE; CASTASTERONE; INTERMEDIATE; PERMANGANATE; DOLICHOLIDE;
Keywords:
28-HOMOBRASSINOLIDE SYNTHESIS; CIS-DIHYDROXYLATION; TETRADECYLTRIMETHYLAMMONIUM PERMANGANATE; TRIFLUOROPEROXYACETIC ACID; CATION-EXCHANGE RESIN AMBERLYST 15;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
31
Recensione:
Indirizzi per estratti:
Citazione:
B.G. Hazra et al., "NEW SYNTHESIS OF 28-HOMOBRASSINOLIDE FROM STIGMASTEROL", Liebigs Annalen, (5), 1997, pp. 1029-1034

Abstract

An efficient and short synthesis of 28-homobrassinolide (6) has been achieved in 12 steps with 15.6% overall yield from stigmasterol (8). Salient features of this synthesis are: (a) use of tetradecyltrimethylammonium permanganate for chemoselective cis-dihydroxylation of the 2,22E-dien-6-one 9, avoiding the use of OsO4; (b) one-step epoxidation ofthe (22E)-olefin and Baeyer-Villiger oxidation of the B-ring ketone 11 with trifluoroperoxyacetic add; and (c) regioselective ring-opening of the 22,23-epoxide 12 to the bromohydrin 13 with LiBr and Amberlyst-15 resin under mild conditions and in excellent yield.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 12/07/20 alle ore 03:19:50