Diastereoselective Approaches to trans-Hydrindane Derivatives − Total Synthesis of 8-(Phenylsulfonyl)de-A,B-cholestane Precursors to 25-Hydroxyvitamin D3

✍ Scribed by Igor Prowotorow; Wiaczesław Stepanenko; Jerzy Wicha

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 177 KB
• Volume: 2002
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/1099-0690(200208)2002:16<2727::aid-ejoc2727>3.0.co;2-1

✦ Synopsis

The total diastereoselective synthesis of the C,D rings/side chain building block for the synthesis of 1α,25-dihydroxyvitamin D 3 is described. Two tandem Mukaiyama-Michael additions involving silylated ketene acetals derived from tert-butyl 6-methylhept-5-enethioate or tert-butyl 6-methylhept-6enethioate, 2-methylcyclopent-2-en-1-one, and 1-(phenylthio)but-3-en-2-one afforded the corresponding intermediates with the complete carbon framework of the target compound. The further transformation of these key interme- [a]