Details

Autor(en) / Beteiligte

• Kurek-Tyrlik, Alicja
• Makaeva, Fliur Z.
• Wicha, Jerzy
• Calverley, Martin J.

Titel

Synthesis of 21-(3-Methylbutyl)cholest-5-ene-3β,3′,25-triol and 21-(2-Methylpropoxy)cholest-5-ene-2′,3β,25-triol, the First "Double Side Chain" Cholesterol Analogues

Ist Teil von

• Liebigs Annalen, 1997-09, Vol.1997 (9), p.1997-2001

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

1997

Quelle

Wiley Online Library

Beschreibungen/Notizen

• The 21‐(3‐hydroxy‐3‐methylbutyl)‐ and 21‐(2‐hydroxy‐2‐methylpropoxy)cholestane derivatives 3 and 5, formally double chain hybrid (20R)‐ and (20S)‐cholesterol analogues, were synthesized. The C‐22 to C‐27 section of the 25‐hydroxycholestane side chain was established by stereoselective alkylation with 5‐bromo‐2‐methyl‐2‐(triethylsilyl)oxypentane of the pregnanoic ester 8, derived from 3β‐acetoxyandrost‐5‐en‐17‐one (7). Reduction of the ester 9 to the 21‐alcohol 10 permitted elaboration of a second hydroxylated side chain, either via the tosylate 11 by alkynation/hydrogenation (yielding intermediate 13) or by alkylation of 10 with bromoacetate (yielding 14) followed by reaction with methyl magnesium bromide.