Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Alkylation reactions sterol side chain

Similar types of alkylation have been applied in syntheses of other steroidal side-chains, including that of 22-trans-26,27-dinorergosta-5,22-dien-3j8-ol (387), a novel marine sterol. In addition, the Wittig reaction has been used to prepare various possible polyene intermediates in phytosterol biosynthesis. The aldehydes (389) and (390) were prepared (Scheme 26) from stigmasterol acetate (388b) by modification of a known procedure. These aldehydes were then alkylated with a variety of ylides derived from phosphonium salts, leading to a series of polyenes (391) and (392). ... [Pg.401]

We have seen that much detailed information is now available on the biosynthesis of plant sterols this includes the isolation of enzymes which form squalene epoxide and cyclize it to cycloartenol, elucidation of the pathways of alkylation leading to 24-alkyl sterols with opposite chirality at C-24, demonstration of the stereospecificity of reactions involving the A -> A -> A - A steps and desaturation of the side chain at C-22 and the removal of... [Pg.504]


See other pages where Alkylation reactions sterol side chain is mentioned: [Pg.132]    [Pg.83]    [Pg.254]    [Pg.5018]    [Pg.389]    [Pg.480]    [Pg.14]    [Pg.449]   
See also in sourсe #XX -- [ Pg.178 , Pg.179 , Pg.180 , Pg.181 , Pg.182 , Pg.183 ]




SEARCH



Alkylation side reactions

Alkylation side-chain

Side chain reactions

Side-chain reactions alkylation

Sterol side chain

© 2024 chempedia.info